Methods and Compositions for Inducing an Immune Response Against Hepatitis B Virus (HBV)

ABSTRACT

Provided herein are Modified Vaccinia Ankara (MVA) vectors and adenovirus vectors encoding HBV antigens. Also provided are methods of enhancing an immune response in a human subject by utilizing the MVA and adenovirus vectors encoding HBV antigens in a prime/boost regimen to the enhance the immune response in the human subject.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims is a divisional application of U.S. patentapplication Ser. No. 16/223,400, filed Dec. 18, 2018, now allowed, whichclaims priority to U.S. Provisional Patent Application No. 62/607,439,filed Dec. 19, 2017, the disclosures of which are each incorporatedherein by reference in their entireties.

REFERENCE TO SEQUENCE LISTING SUBMITTED ELECTRONICALLY

This application contains a sequence listing, which is submittedelectronically via EFS-Web as an ASCII formatted sequence listing with afile name “065814.3US3_SL” and a creation date of May 7, 2021, andhaving a size of 49.6 KB. The sequence listing submitted via EFS-Web ispart of the specification and is herein incorporated by reference in itsentirety.

FIELD OF THE INVENTION

This invention relates to biotechnology. More particularly, theinvention relates to methods and compositions for enhancing an immuneresponse to Hepatitis B Virus (HBV) in a subject in need thereof.

BACKGROUND OF THE INVENTION

Hepatitis B virus (HBV) is a small 3.2-kb hepatotropic DNA virus thatencodes four open reading frames and seven proteins. About two billionpeople are infected with HBV, and approximately 240 million people havechronic hepatitis B infection (chronic HBV), characterized by persistentvirus and subvirus particles in the blood for more than 6 months (1).Persistent HBV infection leads to T-cell exhaustion in circulating andintrahepatic HBV-specific CD4+ and CD8+ T-cells through chronicstimulation of HBV-specific T-cell receptors with viral peptides andcirculating antigens. As a result, T-cell polyfunctionality is decreased(i.e., decreased levels of IL-2, tumor necrosis factor (TNF)-α, IFN-γ,and lack of proliferation).

A safe and effective prophylactic vaccine against HBV infection has beenavailable since the 1980s and is the mainstay of hepatitis B prevention(3). The World Health Organization recommends vaccination of allinfants, and, in countries where there is low or intermediate hepatitisB endemicity, vaccination of all children and adolescents (<18 years ofage), and of people of certain at risk population categories. Due tovaccination, worldwide infection rates have dropped dramatically.However, prophylactic vaccines do not cure established HBV infection.

Chronic HBV is currently treated with IFN-α and nucleoside or nucleotideanalogs, but there is no ultimate cure due to the persistence ininfected hepatocytes of an intracellular viral replication intermediatecalled covalently closed circular DNA (cccDNA), which plays afundamental role as a template for viral RNAs, and thus new virions. Itis thought that induced virus-specific T-cell and B-cell responses caneffectively eliminate cccDNA-carrying hepatocytes. Current therapiestargeting the HBV polymerase suppress viremia, but offer limited effecton cccDNA that resides in the nucleus and related production ofcirculating antigen. The most rigorous form of a cure may be eliminationof HBV cccDNA from the organism, which has neither been observed as anaturally occurring outcome nor as a result of any therapeuticintervention. However, loss of HBV surface antigens (HBsAg) is aclinically credible equivalent of a cure, since disease relapse canoccur only in cases of severe immunosuppression, which can then beprevented by prophylactic treatment. Thus, at least from a clinicalstandpoint, loss of HBsAg is associated with the most stringent form ofimmune reconstitution against HBV.

For example, immune modulation with pegylated interferon (pegIFN)-α hasproven better in comparison to nucleoside or nucleotide therapy in termsof sustained off-treatment response with a finite treatment course.Besides a direct antiviral effect, IFN-α is reported to exert epigeneticsuppression of cccDNA in cell culture and humanized mice, which leads toreduction of virion productivity and transcripts (4). However, thistherapy is still fraught with side-effects and overall responses arerather low, in part because IFN-α has only poor modulatory influences onHBV-specific T-cells. In particular, cure rates are low (<10%) andtoxicity is high. Likewise, direct acting HBV antivirals, namely the HBVpolymerase inhibitors entecavir and tenofovir, are effective asmonotherapy in inducing viral suppression with a high genetic barrier toemergence of drug resistant mutants and consecutive prevention of liverdisease progression. However, cure of chronic hepatitis B, defined byHBsAg loss or seroconversion, is rarely achieved with such HBVpolymerase inhibitors. Therefore, these antivirals in theory need to beadministered indefinitely to prevent reoccurrence of liver disease,similar to antiretroviral therapy for human immunodeficiency virus(HIV).

Therapeutic vaccination has the potential to eliminate HBV fromchronically infected patients (5). Many strategies have been explored,but to date therapeutic vaccination has not proven successful.

BRIEF SUMMARY OF THE INVENTION

Accordingly, there is an unmet medical need in the treatment ofhepatitis B virus (HBV), particularly chronic HBV, for a finitewell-tolerated treatment with a higher cure rate. The applicationsatisfies this need. Provided are Modified Vaccinia Ankara (MVA)vectors. An MVA vector of the application comprises a non-naturallyoccurring nucleic acid molecule comprising a first polynucleotidesequence encoding an HBV polymerase antigen comprising an amino acidsequence that is at least 98% identical to SEQ ID NO: 4. The HBVpolymerase antigen of the MVA vectors can, for example, be capable ofinducing an immune response in a mammal against at least two HBVgenotypes. Preferably, the HBV polymerase antigen is capable of inducinga T cell response in a mammal against at least HBV genotypes B, C, andD. More preferably the HBV polymerase antigen is capable of inducing aCD8 T cell response in a human subject against at least HBV genotypes A,B, C, and D. In an embodiment of the application, an HBV polymeraseantigen comprises the amino acid sequence of SEQ ID NO: 4. In anembodiment of the application, the first polynucleotide sequence is atleast 90% identical to SEQ ID NO: 3. In an embodiment of theapplication, the first polynucleotide sequence comprises thepolynucleotide sequence of SEQ ID NO: 3.

In an embodiment of the application, an MVA vector can further comprisea polynucleotide sequence encoding a signal sequence operably linked tothe HBV polymerase antigen. The signal sequence can, for example,comprise an amino acid sequence of SEQ ID NO: 6 or SEQ ID NO: 11.Preferably, the signal sequence is encoded by the polynucleotidesequence of SEQ ID NO: 5 or SEQ ID NO: 10.

In an embodiment of the application, an MVA vector further comprises asecond polynucleotide sequence encoding a truncated HBV core antigenconsisting of the amino acid sequence of SEQ ID NO: 2. In an embodimentof the application, the second polynucleotide sequence is at least 90%identical to SEQ ID NO: 1. In an embodiment of the application, thesecond polynucleotide sequence comprises the polynucleotide sequence ofSEQ ID NO: 1.

Also provided are compositions comprising an MVA vector of theapplication and a pharmaceutically acceptable carrier.

Also provided are methods of enhancing an immune response in a humansubject in need thereof. The methods comprise (a) administering to thehuman subject a first composition comprising an immunologicallyeffective amount of an adenovirus vector comprising a non-naturallyoccurring nucleic acid molecule comprising a first polynucleotidesequence encoding an HBV polymerase antigen comprising an amino acidsequence that is at least 98% identical to SEQ ID NO:4; and (b)administering to the human subject a second composition comprising animmunologically effective amount of an MVA vector of the application; tothereby obtain an enhanced immune response against the HBV antigen inthe human subject. In an embodiment of the application, the HBVpolymerase antigen does not have reverse transcriptase activity andRNase H activity. In an embodiment of the application, the firstcomposition is for priming the immune response, and the secondcomposition is for boosting the immune response in the subject in needthereof. In an embodiment of the application, step (b) is conducted 1-12weeks after step (a). In an embodiment of the application, step (b) isconducted 2-12 weeks after step (a). In an embodiment of theapplication, step (b) is conducted at least 1 week after step (a). In anembodiment of the application, step (b) is conducted at least 2 weeksafter step (a).

In an embodiment of the application, an HBV polymerase antigen of thefirst composition is capable of inducing an immune response in the humansubject against at least two HBV genotypes, preferably the HBVpolymerase antigen is capable of inducing a T cell response in the humansubject against at least HBV genotypes B, C, and D, and more preferablythe HBV polymerase antigen is capable of inducing a CD8 T cell responsein the human subject against at least HBV genotypes A, B, C, and D.

In an embodiment of the application, the HBV polymerase antigen of thefirst composition comprises the amino acid sequence of SEQ ID NO: 4. Thefirst polynucleotide sequence of the first composition can, for example,be at least 90% identical to SEQ ID NO: 19. In an embodiment of theapplication, the first polynucleotide sequence of the first compositioncomprises the polynucleotide sequence of SEQ ID NO: 19.

In an embodiment of the application, the nucleic acid molecule of theadenovirus vector in the first composition further comprises a secondpolynucleotide sequence encoding a truncated HBV core antigen consistingof the amino acid sequence of SEQ ID NO: 2. The second polynucleotidesequence of the first composition can, for example, be at least 90%identical to SEQ ID NO: 17. In an embodiment of the application, thesecond polynucleotide sequence of the first composition comprises thepolynucleotide sequence of SEQ ID NO:17.

In an embodiment of the application, the first and second polynucleotidesequences of the first composition encode a fusion protein comprisingthe truncated HBV core antigen operably linked to the HBV polymeraseantigen. The fusion protein of the first composition can, for example,comprise the truncated HBV core antigen operably linked to the HBVpolymerase antigen via a linker. The linker of the first compositioncan, for example, comprise the amino acid sequence of (AlaGly)_(n),wherein n is an integer of 2 to 5. Preferably the linker is encoded by apolynucleotide sequence comprising SEQ ID NO:14. In an embodiment of theapplication, the fusion protein of the first composition comprises theamino acid sequence of SEQ ID NO:12.

In an embodiment of the application, the enhanced immune responsecomprises an enhanced antibody response against the HBV antigen in thehuman subject. The enhanced immune response can, for example, comprisean enhanced CD8+ T cell response against the HBV antigen in the humansubject. The enhanced immune response can, for example, comprise anenhanced CD4+ T cell response against the HBV antigen in the humansubject.

In an embodiment of the application, the adenovirus vector is an rAd26or rAd35 vector.

In an embodiment of the application, a method of enhancing an immuneresponse in a human subject comprises (a) administering to the humansubject a first composition comprising an immunologically effectiveamount of a first plasmid comprising a first non-naturally occurringnucleic acid molecule comprising a first polynucleotide sequenceencoding an HBV polymerase antigen comprising an amino acid sequencethat is at least 98% identical to SEQ ID NO: 4 and a second plasmidcomprising a second non-naturally occurring nucleic acid moleculecomprising a second polynucleotide sequence encoding a truncated HBVcore antigen consisting of the amino acid sequence of SEQ ID NO: 2; and(b) administering to the human subject a second composition comprisingan immunologically effective amount of the MVA vector of theapplication; to thereby obtain an enhanced immune response against theHBV antigen in the human subject. In an embodiment of the application,the HBV polymerase antigen of the first composition does not havereverse transcriptase activity and RNase H activity. In an embodiment ofthe application, the first composition is for priming the immuneresponse and the second composition is for boosting the immune response.In an embodiment of the application, step (b) is conducted 1-12 weeksafter step (a). In an embodiment of the application, step (b) isconducted 2-12 weeks after step (a). In an embodiment of theapplication, step (b) is conducted at least 1 week after step (a). In anembodiment of the application, step (b) is conducted at least 2 weeksafter step (a).

In an embodiment of the application, the HBV polymerase antigen of thefirst composition is capable of inducing an immune response in the humansubject against at least two HBV genotypes, preferably the HBVpolymerase antigen is capable of inducing a T cell response in the humansubject against at least HBV genotypes B, C, and D, and more preferablythe HBV polymerase antigen is capable of inducing a CD8 T cell responsein the human subject against at least HBV genotypes A, B, C, and D.

In an embodiment of the application, the HBV polymerase antigen of thefirst composition comprises the amino acid sequence of SEQ ID NO: 4. Thefirst polynucleotide sequence of the first composition can, for example,be at least 90% identical to SEQ ID NO:19. In an embodiment of theapplication, the first polynucleotide sequence of the first compositioncomprises the polynucleotide sequence of SEQ ID NO:19.

In an embodiment of the application, the HBV polymerase antigen of thefirst composition comprises the amino acid sequence of SEQ ID NO: 4. Inan embodiment of the application, the first polynucleotide sequence ofthe first composition is at least 90% identical to SEQ ID NO: 20. Thefirst polynucleotide sequence of the first composition can, for example,comprise SEQ ID NO: 20.

In an embodiment of the application, the nucleic acid molecule of thefirst plasmid of the first composition further comprises apolynucleotide sequence encoding a signal sequence operably linked tothe HBV polymerase antigen of the first composition. The signal sequencecan, for example, comprise the amino acid sequence of SEQ ID NO: 6 orSEQ ID NO: 11, preferably the signal sequence is encoded by thepolynucleotide sequence of SEQ ID NO: 5 or SEQ ID NO: 10.

In an embodiment of the application, the second polynucleotide sequenceof the first composition is at least 90% identical to SEQ ID NO: 18. Thesecond polynucleotide sequence of the first composition can, forexample, comprise the polynucleotide sequence of SEQ ID NO: 18.

In an embodiment of the application, the first and second polynucleotidesequences of the first composition further comprise a promoter sequence,optionally one or more additional regulatory sequences, preferably thepromoter sequence comprises the polynucleotide sequence of SEQ ID NO: 7,and the additional regulatory sequence is selected from the groupconsisting of an enhancer sequence of SEQ ID NO: 8 or SEQ ID NO: 15, anda polyadenylation signal sequence of SEQ ID NO: 16.

In an embodiment of the application, the enhanced immune responsecomprises an enhanced antibody response against the HBV antigen in thehuman subject. The enhanced immune response can, for example, comprisean enhanced CD8+ T cell response against the HBV antigen in the humansubject. The enhanced immune response can, for example, comprise anenhanced CD4+ T cell response against the HBV antigen in the humansubject.

Other aspects, features and advantages of the invention will be apparentfrom the following disclosure, including the detailed description of theinvention and its preferred embodiments and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing summary, as well as the following detailed description ofthe invention, will be better understood when read in conjunction withthe appended drawings. It should be understood that the invention is notlimited to the precise embodiments shown in the drawings.

In the drawings:

FIGS. 1A-1B depict the genome and viral life cycle of hepatitis B virus;FIG. 1A is a diagram of the genome of hepatitis B virus (HBV); in thenative virus, the polymerase protein (Pol) contains the coding sequencefor the envelope proteins in a different open reading frame; theenvelope proteins (pre-S1, pre-S2, and S) are in the same open readingframe; FIG. 1B shows the viral life cycle of HBV;

FIGS. 2A-2C show the schematic representations of the expressioncassettes in adenoviral and MVA vectors according to embodiments of theapplication; FIG. 2A shows the expression cassette for a truncated HBVcore antigen, which contains a CMV promoter, an intron (a fragmentderived from the human ApoAI gene—GenBank accession X01038 base pairs295-523, harboring the ApoAI second intron), a human immunoglobulinsecretion signal, followed by a coding sequence for a truncated HBV coreantigen and a SV40 polyadenylation signal; FIG. 2B shows the expressioncassette for a fusion protein of a truncated HBV core antigen operablylinked to a HBV polymerase antigen, which is otherwise identical to theexpression cassette for the truncated HBV core antigen except the HBVantigen; FIG. 2C shows an expression cassette comprising a HBV coreantigen operably linked to a Pr13.5 long promoter and an expressioncassette comprising a HBV polymerase antigen operably linked to a PrHybpromoter;

FIG. 3 shows a graph of ELISPOT responses of F1 mice immunized withdifferent combinations of HBV adenoviral vectors and HBV MVA; HBV coreor polymerase peptide pools used to stimulate splenocytes isolated fromthe various vaccinated animal groups are indicated in black (core) andgrey (pol). Pol1 and pol2 responses were summed; the X-axis shows theadenovector dose and the presence or absence of the MVA boost; thenumber of responsive T-cells are indicated on the y-axis expressed asspot forming cells (SFC) per 10⁶ splenocytes;

FIG. 4 shows a graph of intracellular cytokine staining (ICS) responsesof F1 mice immunized with different combinations of HBV adenoviralvectors and HBV MVA; HBV core and polymerase peptide pools used tostimulate splenocytes isolated from the various vaccinated animal groupsare indicated in black (core) and grey (pol); Pol1 and pol2 responseswere summed; the X-axis shows the adenovirus vector dose and thepresence or absence of the MVA boost. The percentages of CD8(+) T cellspositive for IFN γ are shown on the y-axis;

FIG. 5 shows a graph of ICS responses of F1 mice immunized withdifferent combinations of HBV adenoviral vectors and HBV MVA vectors;HBV core and polymerase peptide pools used to stimulate splenocytesisolated from the various vaccinated animal groups are indicated inblack (core) and grey (pol); Pol1 and pol2 responses were summed; theX-axis shows the adenoviral vector dose and the presence or absence ofthe MVA boost; the percentages of CD4(+) T cells positive for IFN γ areshown on the y-axis;

FIG. 6 shows a graph of ELISPOT responses of NHPs immunized withdifferent combinations of HBV adenoviral vectors and HBV MVA vectors;HBV core or polymerase peptide pools used to stimulate PBMCs isolatedfrom the various vaccinated animal groups are indicated in squares(core), circles (pol1) and triangles (pol2); the X-axis shows thedifferent experimental groups and timepoints. The number of responsiveT-cells are indicated on the y-axis expressed as spot forming cells(SFC) per 10⁶ splenocytes; background (medium+DMSO stimulation)subtracted data is shown; and

FIGS. 7A, 7B and 7C show graphs of ICS responses of NHPs immunized withdifferent combinations of HBV adenoviral vectors and HBV MVA vectors;HBV core and polymerase peptide pools used to stimulate PBMCs isolatedfrom the various vaccinated animal groups are indicated in squares(core), circles (pol1) and triangles (pol2); the X-axis shows thedifferent experimental groups and time points; the percentages of CD4(+)and CD8(+) T cells positive for IFN γ are shown on the y-axis;background (medium+DMSO stimulation) subtracted data is shown.

DETAILED DESCRIPTION OF THE INVENTION

Various publications, articles and patents are cited or described in thebackground and throughout the specification; each of these references isherein incorporated by reference in its entirety. Discussion ofdocuments, acts, materials, devices, articles or the like which has beenincluded in the present specification is for the purpose of providingcontext for the invention. Such discussion is not an admission that anyor all of these matters form part of the prior art with respect to anyinventions disclosed or claimed.

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as commonly understood to one of ordinary skill inthe art to which this invention pertains. Otherwise, certain terms usedherein have the meanings as set forth in the specification.

It must be noted that as used herein and in the appended claims, thesingular forms “a,” “an,” and “the” include plural reference unless thecontext clearly dictates otherwise.

Unless otherwise stated, any numerical values, such as a concentrationor a concentration range described herein, are to be understood as beingmodified in all instances by the term “about.” Thus, a numerical valuetypically includes ±10% of the recited value. For example, aconcentration of 1 mg/mL includes 0.9 mg/mL to 1.1 mg/mL. Likewise, aconcentration range of 1% to 10% (w/v) includes 0.9% (w/v) to 11% (w/v).As used herein, the use of a numerical range expressly includes allpossible subranges, all individual numerical values within that range,including integers within such ranges and fractions of the values unlessthe context clearly indicates otherwise.

Unless otherwise indicated, the term “at least” preceding a series ofelements is to be understood to refer to every element in the series.Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, many equivalents to the specificembodiments of the invention described herein. Such equivalents areintended to be encompassed by the invention.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, and variations such as“comprises” and “comprising”, will be understood to imply the inclusionof a stated integer or step or group of integers or steps but not theexclusion of any other integer or step or group of integer or step. Whenused herein the term “comprising” can be substituted with the term“containing” or “including” or sometimes when used herein with the term“having”.

When used herein “consisting of” excludes any element, step, oringredient not specified in the claim element. When used herein,“consisting essentially of” does not exclude materials or steps that donot materially affect the basic and novel characteristics of the claim.Any of the aforementioned terms of “comprising,” “containing,”“including,” and “having,” whenever used herein in the context of anaspect or embodiment of the invention can be replaced with the term“consisting of” or “consisting essentially of” to vary scopes of thedisclosure.

As used herein, the conjunctive term “and/or” between multiple recitedelements is understood as encompassing both individual and combinedoptions. For instance, where two elements are conjoined by “and/or,” afirst option refers to the applicability of the first element withoutthe second. A second option refers to the applicability of the secondelement without the first. A third option refers to the applicability ofthe first and second elements together. Any one of these options isunderstood to fall within the meaning, and therefore satisfy therequirement of the term “and/or” as used herein. Concurrentapplicability of more than one of the options is also understood to fallwithin the meaning, and therefore satisfy the requirement of the term“and/or.”

As used herein, “subject” means any animal, preferably a mammal, mostpreferably a human, to whom will be or has been treated by a methodaccording to an embodiment of the application. The term “mammal” as usedherein, encompasses any mammal. Examples of mammals include, but are notlimited to, cows, horses, sheep, pigs, cats, dogs, mice, rats, rabbits,guinea pigs, non-human primates (NHPs), such as monkeys or apes, humans,etc., more preferably a human.

The terms “adjuvant” and “immune stimulant” are used interchangeablyherein, and are defined as one or more substances that cause stimulationof the immune system. In this context, an adjuvant is used to enhance animmune response to the adenovirus and/or MVA vectors of the application.

It should also be understood that the terms “about,” “approximately,”“generally,” “substantially” and like terms, used herein when referringto a dimension or characteristic of a component of the preferredinvention, indicate that the described dimension/characteristic is not astrict boundary or parameter and does not exclude minor variationstherefrom that are functionally the same or similar, as would beunderstood by one having ordinary skill in the art. At a minimum, suchreferences that include a numerical parameter would include variationsthat, using mathematical and industrial principles accepted in the art(e.g., rounding, measurement or other systematic errors, manufacturingtolerances, etc.), would not vary the least significant digit.

The terms “identical” or percent “identity,” in the context of two ormore nucleic acids or polypeptide sequences (e.g., HBV antigenicpolypeptides and polynucleotides that encode them), refer to two or moresequences or subsequences that are the same or have a specifiedpercentage of amino acid residues or nucleotides that are the same, whencompared and aligned for maximum correspondence, as measured using oneof the following sequence comparison algorithms or by visual inspection.

For sequence comparison, typically one sequence acts as a referencesequence, to which test sequences are compared. When using a sequencecomparison algorithm, test and reference sequences are input into acomputer, subsequence coordinates are designated, if necessary, andsequence algorithm program parameters are designated. The sequencecomparison algorithm then calculates the percent sequence identity forthe test sequence(s) relative to the reference sequence, based on thedesignated program parameters.

Optimal alignment of sequences for comparison can be conducted, e.g., bythe local homology algorithm of Smith & Waterman, Adv. Appl. Math. 2:482(1981), by the homology alignment algorithm of Needleman & Wunsch, J.Mol. Biol. 48:443 (1970), by the search for similarity method of Pearson& Lipman, Proc. Nat'l. Acad. Sci. USA 85:2444 (1988), by computerizedimplementations of these algorithms (GAP, BESTFIT, FASTA, and TFASTA inthe Wisconsin Genetics Software Package, Genetics Computer Group, 575Science Dr., Madison, Wis.), or by visual inspection (see generally,Current Protocols in Molecular Biology, F. M. Ausubel et al., eds.,Current Protocols, a joint venture between Greene Publishing Associates,Inc. and John Wiley & Sons, Inc., (1995 Supplement) (Ausubel)).

Examples of algorithms that are suitable for determining percentsequence identity and sequence similarity are the BLAST and BLAST 2.0algorithms, which are described in Altschul et al. (1990) J. Mol. Biol.215: 403-410 and Altschul et al. (1997) Nucleic Acids Res. 25:3389-3402, respectively. Software for performing BLAST analyses ispublicly available through the National Center for BiotechnologyInformation. This algorithm involves first identifying high scoringsequence pairs (HSPs) by identifying short words of length W in thequery sequence, which either match or satisfy some positive-valuedthreshold score T when aligned with a word of the same length in adatabase sequence. T is referred to as the neighborhood word scorethreshold (Altschul et al, supra). These initial neighborhood word hitsact as seeds for initiating searches to find longer HSPs containingthem. The word hits are then extended in both directions along eachsequence for as far as the cumulative alignment score can be increased.

Cumulative scores are calculated using, for nucleotide sequences, theparameters M (reward score for a pair of matching residues; always >0)and N (penalty score for mismatching residues; always <0). For aminoacid sequences, a scoring matrix is used to calculate the cumulativescore. Extension of the word hits in each direction are halted when: thecumulative alignment score falls off by the quantity X from its maximumachieved value; the cumulative score goes to zero or below, due to theaccumulation of one or more negative-scoring residue alignments; or theend of either sequence is reached. The BLAST algorithm parameters W, T,and X determine the sensitivity and speed of the alignment. The BLASTNprogram (for nucleotide sequences) uses as defaults a wordlength (W) of11, an expectation (E) of 10, M=5, N=−4, and a comparison of bothstrands. For amino acid sequences, the BLASTP program uses as defaults awordlength (W) of 3, an expectation (E) of 10, and the BLOSUM62 scoringmatrix (see Henikoff & Henikoff, Proc. Natl. Acad. Sci. USA 89:10915(1989)).

In addition to calculating percent sequence identity, the BLASTalgorithm also performs a statistical analysis of the similarity betweentwo sequences (see, e.g., Karlin & Altschul, Proc. Nat'l. Acad. Sci. USA90:5873-5787 (1993)). One measure of similarity provided by the BLASTalgorithm is the smallest sum probability (P(N)), which provides anindication of the probability by which a match between two nucleotide oramino acid sequences would occur by chance. For example, a nucleic acidis considered similar to a reference sequence if the smallest sumprobability in a comparison of the test nucleic acid to the referencenucleic acid is less than about 0.1, more preferably less than about0.01, and most preferably less than about 0.001.

A further indication that two nucleic acid sequences or polypeptides aresubstantially identical is that the polypeptide encoded by the firstnucleic acid is immunologically cross reactive with the polypeptideencoded by the second nucleic acid, as described below. Thus, apolypeptide is typically substantially identical to a secondpolypeptide, for example, where the two peptides differ only byconservative substitutions. Another indication that two nucleic acidsequences are substantially identical is that the two moleculeshybridize to each other under stringent conditions, as described below.

As used herein, the term “enhanced” when used with respect to an immuneresponse, such as a CD4+ T cell response, an antibody response, or aCD8+ T cell response, refers to an increase in the immune response in asubject administered with a prime-boost combination of MVA andadenovirus vectors according to the application, relative to thecorresponding immune response observed from the subject administeredwith an MVA vector or an adenovirus of the application alone.

As used herein, the term “CD4+ or CD8+ T cell response” refers to a Tcell immune response that is characterized by observing a highproportion of immunogen-specific CD4+ T cells or CD8+ T cells within thepopulation of total responding T cells following vaccination. The totalimmunogen-specific T-cell response can be determined by an IFN-gammaELISPOT assay. The immunogen-specific CD4+ or CD8+ T cell immuneresponse can be determined by an ICS assay.

As used herein, the term “enhanced antibody response” refers to anincreased antibody response in a subject administered with a prime-boostcombination of MVA and adenovirus vectors according to the application,relative to the corresponding immune response observed from the subjectadministered with an MVA vector or an adenovirus of the applicationalone.

The term “adjuvant” is defined as one or more substances that causestimulation of the immune system. In this context, an adjuvant is usedto enhance an immune response to the plasmid, adenovirus, and/or MVAvectors of the application.

As used herein, the term “antigenic gene product or fragment thereof” or“antigenic protein” can include a bacterial, viral, parasitic, or fungalprotein, or a fragment thereof. Preferably, an antigenic protein orantigenic gene product is capable of raising in a host a protectiveimmune response, e.g., inducing an immune response against a disease orinfection (e.g., a bacterial, viral, parasitic, or fungal disease orinfection), and/or producing an immunity in (i.e., vaccinating) asubject against a disease or infection, that protects the subjectagainst the disease or infection.

In an attempt to help the reader of the application, the description hasbeen separated in various paragraphs or sections, or is directed tovarious embodiments of the application. These separations should not beconsidered as disconnecting the substance of a paragraph or section orembodiments from the substance of another paragraph or section orembodiments. To the contrary, one skilled in the art will understandthat the description has broad application and encompasses all thecombinations of the various sections, paragraphs and sentences that canbe contemplated. The discussion of any embodiment is meant only to beexemplary and is not intended to suggest that the scope of thedisclosure, including the claims, is limited to these examples. Forexample, while embodiments of HBV vectors of the application (e.g.,plasmid DNA or viral vectors) described herein may contain particularcomponents, including, but not limited to, certain promoter sequences,enhancer or regulatory sequences, signal peptides, coding sequence of anHBV antigen, polyadenylation signal sequences, etc. arranged in aparticular order, those having ordinary skill in the art will appreciatethat the concepts disclosed herein may equally apply to other componentsarranged in other orders that can be used in HBV vectors of theapplication. The application contemplates use of any of the applicablecomponents in any combination having any sequence that can be used inHBV vectors of the application, whether or not a particular combinationis expressly described.

Hepatitis B Virus (HBV)

As used herein “hepatitis B virus” or “HBV” refers to a virus of thehepadnaviridae family. HBV is a small (e.g., 3.2 kb) hepatotropic DNAvirus that encodes four open reading frames and seven proteins. See FIG.1A. The seven proteins encoded by HBV include small (S), medium (M), andlarge (L) surface antigen (HBsAg) or envelope (Env) proteins, pre-Coreprotein, core protein, viral polymerase (Pol), and HBx protein. HBVexpresses three surface antigens, or envelope proteins, L, M, and S,with S being the smallest and L being the largest. The extra domains inthe M and L proteins are named Pre-S2 and Pre-S1, respectively. Coreprotein is the subunit of the viral nucleocapsid. Pol is needed forsynthesis of viral DNA (reverse transcriptase, RNaseH, and primer),which takes place in nucleocapsids localized to the cytoplasm ofinfected hepatocytes. PreCore is the core protein with an N-terminalsignal peptide and is proteolytically processed at its N and C terminibefore secretion from infected cells, as the so-called hepatitis Be-antigen (HBeAg). HBx protein is required for efficient transcriptionof covalently closed circular DNA (cccDNA). HBx is not a viralstructural protein. All viral proteins of HBV have their own mRNA exceptfor core and polymerase, which share an mRNA. With the exception of theprotein pre-Core, none of the HBV viral proteins are subject topost-translational proteolytic processing.

The HBV virion contains a viral envelope, nucleocapsid, and single copyof the partially double-stranded DNA genome. The nucleocapsid comprises120 dimers of core protein and is covered by a capsid membrane embeddedwith the S, M, and L viral envelope or surface antigen proteins. Afterentry into the cell, the virus is uncoated and the capsid-containingrelaxed circular DNA (rcDNA) with covalently bound viral polymerasemigrates to the nucleus. During that process, phosphorylation of theCore protein induces structural changes, exposing a nuclear localizationsignal enabling interaction of the capsid with so-called importins.These importins mediate binding of the core protein to nuclear porecomplexes upon which the capsid disassembles and polymerase/rcDNAcomplex is released into the nucleus. Within the nucleus the rcDNAbecomes deproteinized (removal of polymerase) and is converted by hostDNA repair machinery to a covalently closed circular DNA (cccDNA) genomefrom which overlapping transcripts encode for HBeAg, HBsAg, Coreprotein, viral polymerase and HBx protein. Core protein, viralpolymerase, and pre-genomic RNA (pgRNA) associate in the cytoplasm andself-assemble into immature pgRNA-containing capsid particles, whichfurther convert into mature rcDNA-capsids and function as a commonintermediate that is either enveloped and secreted as infections virusparticles or transported back to the nucleus to replenish and maintain astable cccDNA pool. See FIG. 1B.

To date, HBV is divided into four serotypes (adr, adw, ayr, ayw) basedon antigenic epitopes present on the envelope proteins, and into eightgenotypes (A, B, C, D, E, F, G, and H) based on the sequence of theviral genome. The HBV genotypes are distributed over differentgeographic regions. For example, the most prevalent genotypes in Asiaare genotypes B and C. Genotype D is dominant in Africa, the MiddleEast, and India, whereas genotype A is widespread in Northern Europe,sub-Saharan Africa, and West Africa.

HBV Antigens

As used herein, the terms “HBV antigen,” “antigenic polypeptide of HBV,”“HBV antigenic polypeptide,” “HBV antigenic protein,” “HBV immunogenicpolypeptide,” and “HBV immunogen” all refer to a polypeptide capable ofinducing an immune response, e.g., a humoral and/or cellular mediatedresponse, against an HBV in a subject. The HBV antigen can be apolypeptide of HBV, a fragment or epitope thereof, or a combination ofmultiple HBV polypeptides, portions or derivatives thereof. An HBVantigen is capable of raising in a host a protective immune response,e.g., inducing an immune response against a viral disease or infection,and/or producing an immunity (i.e., vaccinates) a subject against aviral disease or infection, that protects the subject against the viraldisease or infection. For example, an HBV antigen can comprise apolypeptide or immunogenic fragment(s) thereof from any HBV protein,such as HBeAg, pre-core protein, HBsAg (S, M, or L proteins), coreprotein, viral polymerase, or HBx protein derived from any HBV genotype,e.g., genotype A, B, C, D, E, F, G, and/or H, or combination thereof.

(1) HBV Core Antigen

As used herein, each of the terms “HBV core antigen,” “HBcAg” and “coreantigen” refers to an HBV antigen capable of inducing an immuneresponse, e.g., a humoral and/or cellular mediated response, against anHBV core protein in a subject. Each of the terms “core,” “corepolypeptide,” and “core protein” refers to the HBV viral core protein.Full-length core antigen is typically 183 amino acids in length andincludes an assembly domain (amino acids 1 to 149) and a nucleic acidbinding domain (amino acids 150 to 183). The 34-residue nucleic acidbinding domain is required for pre-genomic RNA encapsidation. Thisdomain also functions as a nuclear import signal. It comprises 17arginine residues and is highly basic, consistent with its function. HBVcore protein is dimeric in solution, with the dimers self-assemblinginto icosahedral capsids. Each dimer of core protein has four α-helixbundles flanked by an α-helix domain on either side. Truncated HBV coreproteins lacking the nucleic acid binding domain are also capable offorming capsids.

In an embodiment of the application, an HBV antigen is a truncated HBVcore antigen. As used herein, a “truncated HBV core antigen,” refers toan HBV antigen that does not contain the entire length of an HBV coreprotein but is capable of inducing an immune response against the HBVcore protein in a subject. For example, an HBV core antigen can bemodified to delete one or more amino acids of the highly positivelycharged (arginine rich) C-terminal nucleic acid binding domain of thecore antigen, which typically contains seventeen arginine (R) residues.In some embodiments of the application, an HBV core antigen is atruncated HBV core protein. A truncated HBV core antigen of theapplication is preferably a C-terminally truncated HBV core proteinwhich does not comprise the HBV core nuclear import signal and/or atruncated HBV core protein from which the C-terminal HBV core nuclearimport signal has been deleted. In an embodiment of the application, atruncated HBV core antigen comprises a deletion in the C-terminalnucleic acid binding domain, such as a deletion of 1 to 34 amino acidresidues of the C-terminal nucleic acid binding domain, e.g., 1, 2, 3,4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, or 34 amino acid residues,preferably a deletion of all 34 amino acid residues. In a preferredembodiment, a truncated HBV core antigen comprises a deletion in theC-terminal nucleic acid binding domain, preferably all 34 amino acidresidues.

According to embodiments of the application, an HBV core antigen can bea consensus sequence derived from multiple HBV genotypes (e.g.,genotypes A, B, C, D, E, F, G, and H). As used herein, “consensussequence” means an artificial sequence of amino acids based on analignment of amino acid sequences of homologous proteins, e.g., asdetermined by an alignment (e.g., using Clustal Omega) of amino acidsequences of homologous proteins. It can be the calculated order of mostfrequent amino acid residues, found at each position in a sequencealignment, based upon sequences of HBV antigens (e.g., core, pol, etc.)from at least 100 natural HBV isolates. A consensus sequence can benon-naturally occurring and different from the native viral sequences.Consensus sequences can be designed by aligning multiple HBV antigensequences from different sources using a multiple sequence alignmenttool, and at variable alignment positions, selecting the most frequentamino acid. Preferably, a consensus sequence of an HBV antigen isderived from HBV genotypes B, C, and D. The term “consensus antigen” isused to refer to an antigen having a consensus sequence.

A truncated HBV core antigen according to an embodiment of theapplication lacks the nucleic acid binding function, and is capable ofinducing an immune response in a mammal against at least two HBVgenotypes. Preferably the truncated HBV core antigen is capable ofinducing a T cell response in a mammal against at least HBV genotypes B,C and D. More preferably, the truncated HBV core antigen is capable ofinducing a CD8 T cell response in a human subject against at least HBVgenotypes A, B, C and D.

In a preferred embodiment of the application, an HBV core antigen is aconsensus antigen, preferably a consensus antigen derived from HBVgenotypes B, C, and D, more preferably a truncated consensus antigenderived from HBV genotypes B, C, and D. An exemplary truncated HBV coreconsensus antigen according to the application consists of an amino acidsequence that is at least 90% identical to SEQ ID NO: 2, such as atleast 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%,98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%,99.9%, or 100% identical to SEQ ID NO: 2. SEQ ID NO: 2 is a coreconsensus antigen derived from HBV genotypes B, C, and D. SEQ ID NO: 2contains a 34-amino acid C-terminal deletion of the highly positivelycharged (arginine rich) nucleic acid binding domain of the native coreantigen.

In a particular embodiment of the application, an HBV core antigen is atruncated HBV antigen consisting of the amino acid sequence of SEQ IDNO: 2.

(2) HBV Polymerase Antigen

As used herein, the term “HBV polymerase antigen,” “HBV Pol antigen” or“HBV pol antigen” refers to an HBV antigen capable of inducing an immuneresponse, e.g., a humoral and/or cellular mediated response, against anHBV polymerase in a subject. Each of the terms “polymerase,” “polymerasepolypeptide,” “Pol” and “pol” refers to the HBV viral DNA polymerase.The HBV viral DNA polymerase has four domains, including, from the Nterminus to the C terminus, a terminal protein (TP) domain, which actsas a primer for minus-strand DNA synthesis; a spacer that isnonessential for the polymerase functions; a reverse transcriptase (RT)domain for transcription; and a RNase H domain.

In an embodiment of the application, an HBV antigen comprises an HBV Polantigen, or any immunogenic fragment or combination thereof. The HBV Polantigen can contain further modifications to improve immunogenicity ofthe antigen, such as by introducing mutations into the active sites ofthe polymerase and/or RNase domains to decrease or substantiallyeliminate certain enzymatic activities.

Preferably, an HBV Pol antigen of the application does not have reversetranscriptase activity and RNase H activity, and can be capable ofinducing an immune response in a mammal against at least two HBVgenotypes. Preferably the HBV Pol antigen is capable of inducing a Tcell response in a mammal against at least HBV genotypes B, C and D.More preferably, the HBV Pol antigen is capable of inducing a CD8 T cellresponse in a human subject against at least HBV genotypes A, B, C andD.

Thus, in some embodiments of the application, an HBV Pol antigen is aninactivated Pol antigen. In an embodiment of the application, aninactivated HBV Pol antigen comprises one or more amino acid mutationsin the active site of the polymerase domain. In another embodiment, aninactivated HBV Pol antigen comprises one or more amino acid mutationsin the active site of the RNaseH domain. In a preferred embodiment, aninactivated HBV pol antigen comprises one or more amino acid mutationsin the active site of both the polymerase domain and the RNaseH domain.For example, the “YXDD” motif in the polymerase domain of the HBV polantigen required for nucleotide/metal ion binding can be mutated, e.g.,by replacing one or more of the aspartate residues (D) with asparagineresidues (N), eliminating or reducing metal coordination function,thereby decreasing or substantially eliminating reverse transcriptasefunction. Alternatively, or in addition to mutation of the “YXDD” motif,the “DEDD” motif in the RNaseH domain of the HBV pol antigen requiredfor Mg2+ coordination can be mutated, e.g., by replacing one or moreaspartate residues (D) with asparagine residues (N) and/or replacing theglutamate residue (E) with glutamine (Q), thereby decreasing orsubstantially eliminating RNaseH function. In a particular embodiment,an HBV pol antigen is modified by (1) mutating the aspartate residues(D) to asparagine residues (N) in the “YXDD” motif of the polymerasedomain; and (2) mutating the first aspartate residue (D) to anasparagine residue (N) and the first glutamate residue (E) to aglutamine residue (N) in the “DEDD” motif of the RNaseH domain, therebydecreasing or substantially eliminating both the reverse transcriptaseand RNaseH functions of the pol antigen.

In a preferred embodiment of the application, an HBV pol antigen is aconsensus antigen, preferably a consensus antigen derived from HBVgenotypes B, C, and D, more preferably an inactivated consensus antigenderived from HBV genotypes B, C, and D. An exemplary HBV pol consensusantigen according to the application comprises an amino acid sequencethat is at least 90% identical to SEQ ID NO: 4, such as at least 90%,91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%,99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100%identical to SEQ ID NO: 4, preferably at least 98% identical to SEQ IDNO: 4, such as at least 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%,99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identical to SEQ ID NO: 4. SEQID NO: 4 is a pol consensus antigen derived from HBV genotypes B, C, andD comprising four mutations located in the active sites of thepolymerase and RNaseH domains. In particular, the four mutations includemutation of the aspartic acid residues (D) to asparagine residues (N) inthe “YXDD” motif of the polymerase domain; and mutation of the firstaspartate residue (D) to an asparagine residue (N) and mutation of theglutamate residue (E) to a glutamine residue (Q) in the “DEDD” motif ofthe RNaseH domain.

In a particular embodiment of the application, an HBV pol antigencomprises the amino acid sequence of SEQ ID NO: 4. In other embodimentsof the application, an HBV pol antigen consists of the amino acidsequence of SEQ ID NO: 4.

(3) Fusion of HBV Core Antigen and HBV Polymerase Antigen

As used herein the term “fusion protein” or “fusion” refers to a singlepolypeptide chain having at least two polypeptide domains that are notnormally present in a single, natural polypeptide.

In an embodiment of the application, an HBV antigen comprises a fusionprotein comprising a truncated HBV core antigen operably linked to a HBVpol antigen, or a HBV pol antigen operably linked to a truncated HBVcore antigen, preferably via a linker.

As used herein, the term “linker” refers to a compound or moiety thatacts as a molecular bridge to operably link two different molecules,wherein one portion of the linker is operably linked to a firstmolecule, and wherein another portion of the linker is operably linkedto a second molecule. For example, in a fusion protein containing afirst polypeptide and a second heterologous polypeptide, a linker servesprimarily as a spacer between the first and second polypeptides. In oneembodiment, the linker is made up of amino acids linked together bypeptide bonds, preferably from 1 to 20 amino acids linked by peptidebonds, wherein the amino acids are selected from the 20 naturallyoccurring amino acids. In one embodiment, the 1 to 20 amino acids areselected from glycine, alanine, proline, asparagine, glutamine, andlysine. Preferably, a linker is made up of a majority of amino acidsthat are sterically unhindered, such as glycine and alanine. Exemplarylinkers are polyglycines, particularly (Gly)5, (Gly)8; poly(Gly-Ala),and polyalanines. One exemplary suitable linker as shown in the Examplesbelow is (AlaGly)_(n), wherein n is an integer of 2 to 5.

Preferably, a fusion protein of the application is capable of inducingan immune response in a mammal against HBV core and HBV Pol of at leasttwo HBV genotypes. Preferably the fusion protein is capable of inducinga T cell response in a mammal against at least HBV genotypes B, C and D.More preferably, the fusion protein is capable of inducing a CD8 T cellresponse in a human subject against at least HBV genotypes A, B, C andD.

In an embodiment of the application, a fusion protein comprises atruncated HBV core antigen having an amino acid sequence at least 90%,such as at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%,97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%,99.8%, 99.9%, or 100% identical to SEQ ID NO: 2, a linker, and a HBV polantigen having an amino acid sequence at least 90%, such as at least90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%,99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9%, or100%, identical to SEQ ID NO: 4.

In a preferred embodiment of the application, a fusion protein comprisesa truncated HBV core antigen consisting of the amino acid sequence ofSEQ ID NO: 2, a linker comprising (AlaGly)_(n), wherein n is an integerof 2 to 5, and a HBV Pol antigen having the amino acid sequence of SEQID NO: 4. More preferably, a fusion protein according to an embodimentof the application comprises the amino acid sequence of SEQ ID NO: 12.

In an embodiment of the application, a fusion protein further comprisesa signal sequence. Preferably, the signal sequence has the amino acidsequence of SEQ ID NO: 6 or SEQ ID NO: 11. More preferably, the fusionprotein comprises the amino acid sequence of SEQ ID NO: 13.

Polynucleotides and Vectors

In another general aspect, the application provides a non-naturallyoccurring nucleic acid molecule encoding an HBV antigen according to anembodiment of the application, and a vector comprising the non-naturallyoccurring nucleic acid. A non-naturally occurring nucleic acid moleculecan comprise any polynucleotide sequence encoding an HBV antigen of theapplication, which can be made using methods known in the art in view ofthe present disclosure. Preferably, a polynucleotide encodes at leastone of an HBV core antigen and an HBV polymerase antigen of theapplication. A polynucleotide can be in the form of RNA or in the formof DNA obtained by recombinant techniques (e.g., cloning) or producedsynthetically (e.g., chemical synthesis). The DNA can be single-strandedor double-stranded, or can contain portions of both double-stranded andsingle-stranded sequence. The DNA can, for example, comprise genomicDNA, cDNA, or combinations thereof. The polynucleotide can also be aDNA/RNA hybrid. The polynucleotides and vectors of the application canbe used for recombinant protein production, expression of the protein ina host cell, or the production of viral particles. Preferably, apolynucleotide is DNA.

In an embodiment of the application, a non-naturally occurring nucleicacid molecule comprises a polynucleotide encoding a truncated HBV coreantigen consisting of an amino acid sequence that is at least 90%identical to SEQ ID NO: 2, such as at least 90%, 91%, 92%, 93%, 94%,95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%,99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identical to SEQID NO: 2, preferably at least 98%, 99% or 100% identical to SEQ ID NO:2. In a particular embodiment of the application, a non-naturallyoccurring nucleic acid molecule encodes a truncated HBV core antigencomprising the amino acid sequence of SEQ ID NO: 2.

Examples of polynucleotide sequences of the application encoding atruncated HBV core antigen comprising the amino acid sequence of SEQ IDNO: 2 include, but are not limited to, a polynucleotide sequence atleast 90% identical to SEQ ID NO: 1, such as at least 90%, 91%, 92%,93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%,99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identicalto SEQ ID NO: 1, preferably at least 98%, 99% or 100% identical to SEQID NO: 1. In particular embodiments of the application, thenon-naturally occurring nucleic acid molecule encoding a truncated HBVcore antigen comprises the polynucleotide sequence of SEQ ID NOs: 1, 17,or 18.

In an embodiment of the application, a non-naturally occurring nucleicacid molecule encodes a HBV polymerase antigen comprising an amino acidsequence that is at least 90% identical to SEQ ID NO: 4, such as atleast 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%,98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%,99.9% or 100% identical to SEQ ID NO: 4, preferably 100% identical toSEQ ID NO: 4. In a particular embodiment of the application, anon-naturally occurring nucleic acid molecule encodes a HBV polymeraseantigen comprising the amino acid sequence of SEQ ID NO: 4.

Examples of polynucleotide sequences of the application encoding a HBVPol antigen comprising the amino acid sequence of SEQ ID NO: 4 include,but are not limited to, a polynucleotide sequence at least 90% identicalto SEQ ID NO:3, such as at least 90%, 91%, 92%, 93%, 94%, 95%, 95.5%,96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%,99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identical to SEQ ID NO: 3,preferably at least 98%, 99% or 100% identical to SEQ ID NO: 3. Inparticular embodiments of the application, the non-naturally occurringnucleic acid molecule encoding a HBV pol antigen comprises thepolynucleotide sequence of SEQ ID NOs: 3, 19, or 20.

In another embodiment of the application, a non-naturally occurringnucleic acid molecule encodes a fusion protein comprising a truncatedHBV core antigen operably linked to a HBV Pol antigen, or a HBV Polantigen operably linked to a truncated HBV core antigen. In a particularembodiment, a non-naturally occurring nucleic acid molecule of theapplication encodes a truncated HBV core antigen consisting of an aminoacid sequence that is at least 90% identical to SEQ ID NO: 2, such as atleast 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%,98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%,99.9% or 100% identical to SEQ ID NO: 2, preferably 100% identical toSEQ ID NO: 2; a linker; and a HBV polymerase antigen comprising an aminoacid sequence that is at least 90% identical to SEQ ID NO: 4, such as atleast 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%,98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%,99.9% or 100% identical to SEQ ID NO: 4, preferably at least 98%, 99% or100% identical to SEQ ID NO: 4. In a particular embodiment of theapplication, a non-naturally occurring nucleic acid molecule encodes afusion protein comprising a truncated HBV core antigen consisting of theamino acid sequence of SEQ ID NO: 2, a linker comprising (AlaGly)_(n),wherein n is an integer of 2 to 5; and a HBV Pol antigen comprising theamino acid sequence of SEQ ID NO: 4. In a particular embodiment of theapplication, a non-naturally occurring nucleic acid molecule encodes afusion protein comprising the amino acid sequence of SEQ ID NO: 12.

Examples of polynucleotide sequences of the application encoding afusion protein include, but are not limited to, a polynucleotidesequence at least 90% identical to SEQ ID NO: 1, such as at least 90%,91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%,99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100%identical to SEQ ID NO: 1, preferably at least 98%, 99% or 100%identical to SEQ ID NO: 1, operably linked to a linker coding sequenceat least 90% identical to SEQ ID NO: 14, such as at least 90%, 91%, 92%,93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%,99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identicalto SEQ ID NO: 14, preferably at least 98%, 99% or 100% identical to SEQID NO: 14, which is further operably linked a polynucleotide sequence atleast 90% identical to SEQ ID NO: 3, such as at least 90%, 91%, 92%,93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%,99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identicalto SEQ ID NO: 3, preferably at least 98%, 99% or 100% identical to SEQID NO: 3. In particular embodiments of the application, a non-naturallyoccurring nucleic acid molecule encoding a fusion protein comprises SEQID NO: 1, operably linked to SEQ ID NO:14, which is further operablylinked to SEQ ID NO: 3.

In another general aspect, the application relates to a vectorcomprising an isolated polynucleotide encoding an HBV antigen. As usedherein, a “vector” is a nucleic acid molecule used to carry geneticmaterial into another cell, where it can be replicated and/or expressed.Any vector known to those skilled in the art in view of the presentdisclosure can be used. Examples of vectors include, but are not limitedto, plasmids, viral vectors (bacteriophage, animal viruses, and plantviruses), cosmids, and artificial chromosomes (e.g., YACs). Preferably,a vector is a DNA plasmid. A vector can be a DNA vector or an RNAvector. One of skill in the art can construct a vector of theapplication through standard recombinant techniques in view of thepresent disclosure.

According to embodiments of the application, a vector can be anexpression vector. As used herein, the term “expression vector” refersto any type of genetic construct comprising a nucleic acid coding for anRNA capable of being transcribed. Expression vectors include, but arenot limited to, vectors for recombinant protein expression, such as aDNA plasmid or a viral vector, and vectors for delivery of nucleic acidinto a subject for expression in a tissue of the subject, such as a DNAplasmid or a viral vector. It will be appreciated by those skilled inthe art that the design of the expression vector can depend on suchfactors as the choice of the host cell to be transformed, the level ofexpression of protein desired, etc.

Vectors according to embodiments of the application can contain avariety of regulatory sequences. As used herein, the term “regulatorysequence” refers to any sequence that allows, contributes or modulatesthe functional regulation of the nucleic acid molecule, includingreplication, duplication, transcription, splicing, translation,stability and/or transport of the nucleic acid or one of its derivative(i.e. mRNA) into the host cell or organism. In the context of thedisclosure, this term encompasses promoters, enhancers and otherexpression control elements (e.g., polyadenylation signals and elementsthat affect mRNA stability).

In some embodiments, of the application, a vector is a non-viral vector.Examples of non-viral vectors include, but are not limited to, DNAplasmids, bacterial artificial chromosomes, yeast artificialchromosomes, bacteriophages, etc. Preferably, a non-viral vector is aDNA plasmid. A “DNA plasmid,” which is used interchangeably with “DNAplasmid vector,” “plasmid DNA” or “plasmid DNA vector,” refers to adouble-stranded and generally circular DNA sequence that is capable ofautonomous replication in a suitable host cell. DNA plasmids used forexpression of an encoded polynucleotide typically comprise an origin ofreplication, a multiple cloning site, and a selectable marker, which forexample, can be an antibiotic resistance gene. Examples of DNA plasmidssuitable for use in the application include, but are not limited to,commercially available expression vectors for use in well-knownexpression systems (including both prokaryotic and eukaryotic systems),such as pSE420 (Invitrogen, San Diego, Calif.), which can be used forproduction and/or expression of protein in Escherichia coli; pYES2(Invitrogen, Thermo Fisher Scientific), which can be used for productionand/or expression in Saccharomyces cerevisiae strains of yeast; MAXBAC®complete baculovirus expression system (Thermo Fisher Scientific), whichcan be used for production and/or expression in insect cells; pcDNA™ orpcDNA3™ (Life Technologies, Thermo Fisher Scientific), which can be usedfor high level constitutive protein expression in mammalian cells; andpVAX or pVAX-1 (Life Technologies, Thermo Fisher Scientific), which canbe used for high-level transient expression of a protein of interest inmost mammalian cells. The backbone of any commercially available DNAplasmid can be modified to optimize protein expression in the host cell,such as to reverse the orientation of certain elements (e.g., origin ofreplication and/or antibiotic resistance cassette), replace a promoterendogenous to the plasmid (e.g., the promoter in the antibioticresistance cassette), and/or replace the polynucleotide sequenceencoding transcribed proteins (e.g., the coding sequence of theantibiotic resistance gene), by using routine techniques and readilyavailable starting materials. (See e.g., Sambrook et al., MolecularCloning a Laboratory Manual, Second Ed. Cold Spring Harbor Press(1989)).

In a preferred embodiment of the application, a DNA plasmid is anexpression vector suitable for protein expression in mammalian hostcells. Expression vectors suitable for protein expression in mammalianhost cells include, but are not limited to, pcDNA™, pcDNA3™, pVAX,pVAX-1, ADVAX, NTC8454, etc. Preferably, the expression vector is basedon pVAX-1, which can be further modified to optimize protein expressionin mammalian cells. pVAX-1 is a commonly used plasmid in DNA vaccines,and contains a strong human immediate early cytomegalovirus (CMV-IE)promoter followed by the bovine growth hormone (bGH)-derivedpolyadenylation sequence (pA). pVAX-1 further contains a pUC origin ofreplication and kanamycin resistance gene driven by a small prokaryoticpromoter that allows for bacterial plasmid propagation.

In an embodiment of the application, a vector is a viral vector. Ingeneral, viral vectors are genetically engineered viruses carryingmodified viral DNA or RNA that has been rendered non-infectious, butstill contains viral promoters and transgenes, thus allowing fortranslation of the transgene through a viral promoter. Because viralvectors are frequently lacking infectious sequences, they require helperviruses or packaging lines for large-scale transfection. Examples ofviral vectors suitable for use with the application include, but are notlimited to adenoviral vectors, Modified Vaccinia Ankara (MVA) vectors,adeno-associated virus vectors, pox virus vectors, enteric virusvectors, Venezuelan Equine Encephalitis virus vectors, Semliki ForestVirus vectors, Tobacco Mosaic Virus vectors, lentiviral vectors, etc.

According to embodiments of the application, a vector, e.g., a DNAplasmid or a viral vector, can comprise any regulatory elements toestablish conventional function(s) of the vector, including but notlimited to replication and expression of the HBV antigen(s) encoded bythe polynucleotide sequence of the vector. Regulatory elements include,but are not limited to, a promoter, an enhancer, a polyadenylationsignal, translation stop codon, a ribosome binding element, atranscription terminator, selection markers, origin of replication, etc.A vector can comprise one or more expression cassettes. An “expressioncassette” is part of a vector that directs the cellular machinery tomake RNA and protein. An expression cassette typically comprises threecomponents: a promoter sequence, an open reading frame, and a3′-untranslated region (UTR) optionally comprising a polyadenylationsignal. An open reading frame (ORF) is a reading frame that contains acoding sequence of a protein of interest (e.g., HBV antigen) from astart codon to a stop codon. Regulatory elements of the expressioncassette can be operably linked to a polynucleotide sequence encoding anHBV antigen of interest. As used herein, the term “operably linked” isto be taken in its broadest reasonable context, and refers to a linkageof polynucleotide elements in a functional relationship. Apolynucleotide is “operably linked” when it is placed into a functionalrelationship with another polynucleotide. For instance, a promoter isoperably linked to a coding sequence if it affects the transcription ofthe coding sequence.

In some embodiments, a vector comprises a promoter sequence, preferablywithin an expression cassette, to control expression of an HBV antigenof interest. The term “promoter” is used in its conventional sense, andrefers to a nucleotide sequence that initiates the transcription of anoperably linked nucleotide sequence. A promoter is located on the samestrand near the nucleotide sequence it transcribes. Promoters can be aconstitutive, inducible, or repressible. Promoters can be naturallyoccurring or synthetic. A promoter can be derived from sourcesincluding, viral, bacterial, fungal, plants, insects, and animals. Apromoter can be a homologous promoter (i.e., derived from the samegenetic source as the vector) or a heterologous promoter (i.e., derivedfrom a different vector or genetic source). For example, if the vectorto be employed is a DNA plasmid, the promoter can be endogenous to theplasmid (homologous) or derived from other sources (heterologous).Preferably, the promoter is located upstream of the polynucleotideencoding an HBV antigen within an expression cassette.

Examples of promoters suitable for use in the application include, butare not limited to, a promoter from simian virus 40 (SV40), a mousemammary tumor virus (MMTV) promoter, a human immunodeficiency virus(HIV) promoter such as the bovine immunodeficiency virus (BIV) longterminal repeat (LTR) promoter, a Moloney virus promoter, an avianleukosis virus (ALV) promoter, a cytomegalovirus (CMV) promoter such asthe CMV immediate early promoter (CMV-IE), Epstein Barr virus (EBV)promoter, or a Rous sarcoma virus (RSV) promoter. Additional promoterssuitable for use in the application include, but are not limited to, anRSV promoter, the retrovirus LTR, the adenovirus major late promoter,and various poxvirus promoters including, but not limited to thefollowing vaccinia virus or MVA-derived and FPV-derived promoters: the30K promoter, the 13 promoter, the PrS promoter, the PrHyb, the PrS5Epromoter, the Pr7.5K, the Pr13.5 long promoter, the 40K promoter, theMVA-40K promoter, the FPV 40K promoter, 30k promoter, the PrSynIImpromoter, the PrLE1 promoter, and the PR1238 promoter. Additionalpromoters are further described in WO 2010/060632, WO 2010/102822, WO2013/189611 and WO 2014/063832, and WO2017/021776, which areincorporated fully by reference herein.

A promoter can also be a promoter from a human gene such as human actin,human myosin, human hemoglobin, human muscle creatine, or humanmetalothionein. A promoter can also be a tissue specific promoter, suchas a muscle or skin specific promoter, natural or synthetic.

In a preferred embodiment of the application, a promoter is a strongeukaryotic promoter, preferably a cytomegalovirus immediate early(CMV-IE) promoter. A nucleotide sequence of an exemplary CMV-IE promoteris shown in SEQ ID NO: 7.

In another preferred embodiment of the application, a promoter is apoxviral promoter, preferably a promoter selected from PrMVA 13.5 longand/or PrHyb. Nucleotide sequences for an exemplary Pr13.5 long promoterand a PrHyb promoter are shown as SEQ ID NO:25 and 26, respectively.

In some embodiments, a vector comprises additional polynucleotidesequences that stabilize the expressed transcript, enhance nuclearexport of the RNA transcript, and/or improvetranscriptional-translational coupling. Examples of such sequencesinclude polyadenylation signals and enhancer sequences. Apolyadenylation signal is typically located downstream of the codingsequence for a protein of interest (e.g., an HBV antigen) within anexpression cassette of the vector. Enhancer sequences are regulatory DNAsequences that, when bound by transcription factors, enhance thetranscription of an associated gene. An enhancer sequence is preferablylocated upstream of the polynucleotide sequence encoding an HBV antigen,but downstream of a promoter sequence within an expression cassette ofthe vector.

Any polyadenylation signal known to those skilled in the art in view ofthe present disclosure can be used. For example, the polyadenylationsignal can be a SV40 polyadenylation signal (e.g., SEQ ID NO:16), LTRpolyadenylation signal, bovine growth hormone (bGH) polyadenylationsignal, human growth hormone (hGH) polyadenylation signal, or humanβ-globin polyadenylation signal. In a preferred embodiment of theapplication, a polyadenylation signal is a bovine growth hormone (bGH)polyadenylation signal. A nucleotide sequence of an exemplary bGHpolyadenylation signal is shown in SEQ ID NO:9.

Any enhancer sequence known to those skilled in the art in view of thepresent disclosure can be used. For example, an enhancer sequence can behuman actin, human myosin, human hemoglobin, human muscle creatine, or aviral enhancer, such as one from CMV, HA, RSV, or EBV. Examples ofparticular enhancers include, but are not limited to, Woodchuck HBVPost-transcriptional regulatory element (WPRE), intron/exon sequencederived from human apolipoprotein A1 precursor, untranslated R-U5 domainof the human T-cell leukemia virus type 1 (HTLV-1) long terminal repeat(LTR), a splicing enhancer, a synthetic rabbit β-globin intron, or anycombination thereof. In a preferred embodiment of the application, anenhancer sequence is a composite sequence of three consecutive elementsof the untranslated R-U5 domain of HTLV-1 LTR, rabbit β-globin intron,and a splicing enhancer, which is referred to herein as “a tripleenhancer sequence.” A nucleotide sequence of an exemplary tripleenhancer sequence is shown in SEQ ID NO: 8. Another exemplary enhancersequence is an ApoAI gene fragment shown in SEQ ID NO:15.

In some embodiments, a vector comprises a polynucleotide sequenceencoding a signal peptide sequence. Preferably, the polynucleotidesequence encoding the signal peptide sequence is located upstream of thepolynucleotide sequence encoding an HBV antigen. Signal peptidestypically direct localization of a protein, facilitate secretion of theprotein from the cell in which it is produced, and/or improve antigenexpression and cross-presentation to antigen-presenting cells. A signalpeptide can be present at the N-terminus of an HBV antigen whenexpressed from the vector, but is cleaved off by signal peptidase, e.g.,upon secretion from a cell. An expressed protein in which a signalpeptide has been cleaved is often referred to as the “mature protein.”Any signal peptide known in the art in view of the present disclosurecan be used. For example, a signal peptide can be a cystatin S signalpeptide; an immunoglobulin (Ig) secretion signal, such as the Ig heavychain gamma signal peptide SPIgG or the Ig heavy chain epsilon signalpeptide SPIgE.

In a preferred embodiment of the application, a signal peptide sequenceis a cystatin S signal peptide. Exemplary nucleic acid and amino acidsequences of a cystatin S signal peptide are shown in SEQ ID NOs: 5 and6, respectively. Exemplary nucleic acid and amino acid sequences of animmunoglobulin secretion signal are shown in SEQ ID NOs: 10 and 27 andSEQ ID NO: 11, respectively.

A vector, such as a DNA plasmid, can also include a bacterial origin ofreplication and an antibiotic resistance expression cassette forselection and maintenance of the plasmid in bacterial cells, e.g., E.coli. Bacterial origins of replication and antibiotic resistancecassettes can be located in a vector in the same orientation as theexpression cassette encoding an HBV antigen, or in the opposite(reverse) orientation. An origin of replication (ORI) is a sequence atwhich replication is initiated, enabling a plasmid to reproduce andsurvive within cells. Examples of ORIs suitable for use in theapplication include, but are not limited to ColE1, pMB1, pUC, pSC101,R6K, and 15A, preferably pUC. An exemplary nucleotide sequence of a pUCORI is shown in SEQ ID NO: 21.

Expression cassettes for selection and maintenance in bacterial cellstypically include a promoter sequence operably linked to an antibioticresistance gene. Preferably, the promoter sequence operably linked to anantibiotic resistance gene differs from the promoter sequence operablylinked to a polynucleotide sequence encoding a protein of interest,e.g., HBV antigen. The antibiotic resistance gene can be codonoptimized, and the sequence composition of the antibiotic resistancegene is normally adjusted to bacterial, e.g., E. coli, codon usage. Anyantibiotic resistance gene known to those skilled in the art in view ofthe present disclosure can be used, including, but not limited to,kanamycin resistance gene (Kan^(r)), ampicillin resistance gene(Amp^(r)), and tetracycline resistance gene (Tet^(r)), as well as genesconferring resistance to chloramphenicol, bleomycin, spectinomycin,carbenicillin, etc.

In another particular embodiment of the application, a vector is a viralvector, preferably an adenoviral vector, comprising an expressioncassette including a polynucleotide encoding at least one of an HBVantigen selected from the group consisting of an HBV pol antigencomprising an amino acid sequence at least 98% identical to SEQ ID NO:4, such as at least 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%,99.6%, 99.7%, 99.8%, 99.9% or 100% identical to SEQ ID NO: 4, and atruncated HBV core antigen consisting of the amino acid sequence of SEQID NO: 2; an upstream sequence operably linked to the polynucleotideencoding the HBV antigen comprising, from 5′ end to 3′ end, a promotersequence, preferably a CMV-IE promoter sequence of SEQ ID NO:7, anenhancer sequence, preferably a triple enhancer sequence of SEQ ID NO: 8or an ApoA1 enhancer sequence of SEQ ID NO: 15, and a polynucleotidesequence encoding a signal peptide sequence, preferably a cystatin Ssignal having the amino acid sequence of SEQ ID NO: 6 or animmunoglobulin secretion signal having the amino acid sequence of SEQ IDNO: 11; and a downstream sequence operably linked to the polynucleotideencoding the HBV antigen comprising a polyadenylation signal, preferablya SV40 polyadenylation signal of SEQ ID NO: 16 or a bGH polyadenylationsignal of SEQ ID NO: 9.

In another particular embodiment of the application, a vector is a viralvector, preferably a MVA vector, comprising an expression cassetteincluding a polynucleotide encoding at least one of an HBV antigenselected from the group consisting of an HBV pol antigen comprising anamino acid sequence at least 98% identical to SEQ ID NO: 4, such as atleast 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%,99.8%, 99.9% or 100% identical to SEQ ID NO: 4, and a truncated HBV coreantigen consisting of the amino acid sequence of SEQ ID NO: 2; anupstream sequence operably linked to the polynucleotide encoding the HBVantigen comprising, from 5′ end to 3′ end, a promoter sequence,preferably a PrMVA13.5 long promoter sequence of SEQ ID NO: 25 or aPrHyb promoter sequence of SEQ ID NO: 26, and a polynucleotide sequenceencoding a signal peptide sequence, preferably a cystatin S signalhaving the amino acid sequence of SEQ ID NO: 6 or an immunoglobulinsecretion signal having the amino acid sequence of SEQ ID NO: 11; and adownstream sequence operably linked to the polynucleotide encoding theHBV antigen comprising a polyadenylation signal or an early terminationsignal, wherein the early termination signal has a nucleotide sequenceof SEQ ID NO: 28, or wherein the polyadenylation signal is selected froman SV40 polyadenylation signal having a polynucleotide sequence of SEQID NO: 16 or a bGH polyadenylation signal having a polynucleotidesequence of SEQ ID NO: 9, preferably the downstream sequence operablylinked to the polynucleotide encoding the HBV antigen is an earlytermination signal having a nucleotide sequence of SEQ ID NO: 28.

In an embodiment of the application, a vector, such as a viral vector,encodes an HBV Pol antigen having the amino acid sequence of SEQ ID NO:4. Preferably, the vector comprises a coding sequence for the HBV Polantigen that is at least 90% identical to the polynucleotide sequence ofSEQ ID NO: 3, such as 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%,97%, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%,99.7%, 99.8%, 99.9% or 100% identical to SEQ ID NO: 3, preferably 100%identical to SEQ ID NO: 3.

In another embodiment of the application, a vector, such as a viralvector, encodes a truncated HBV core antigen consisting of the aminoacid sequence of SEQ ID NO:2. Preferably, the vector comprises a codingsequence for the truncated HBV core antigen that is at least 90%identical to the polynucleotide sequence of SEQ ID NO:1, such as 90%,91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%,99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100%identical to SEQ ID NO: 1, preferably 100% identical to SEQ ID NO: 1.

In yet another embodiment of the application, a vector, such as a viralvector, encodes a fusion protein comprising an HBV Pol antigen havingthe amino acid sequence of SEQ ID NO: 4 and a truncated HBV core antigenconsisting of the amino acid sequence of SEQ ID NO: 2. Preferably, thevector comprises a coding sequence for the fusion, which contains acoding sequence for the truncated HBV core antigen at least 90%identical to SEQ ID NO:1, such as 90%, 91%, 92%, 93%, 94%, 95%, 95.5%,96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%,99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identical to SEQ ID NO:1,preferably 98%, 99% or 100% identical to SEQ ID NO: 1, operably linkedto a coding sequence for the HBV Pol antigen at least 90% identical toSEQ ID NO: 3, such as 90%, 91%, 92%, 93%, 94%, 95%, 95.5%, 96%, 96.5%,97%, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%, 99.3%, 99.4%, 99.5%, 99.6%,99.7%, 99.8%, 99.9% or 100% identical to SEQ ID NO:3, preferably 98%,99% or 100% identical to SEQ ID NO: 3. Preferably, the coding sequencefor the truncated HBV core antigen is operably linked to the codingsequence for the HBV Pol antigen via a coding sequence for a linker atleast 90% identical to SEQ ID NO: 14, such as 90%, 91%, 92%, 93%, 94%,95%, 95.5%, 96%, 96.5%, 97%, 97.5%, 98%, 98.5%, 99%, 99.1%, 99.2%,99.3%, 99.4%, 99.5%, 99.6%, 99.7%, 99.8%, 99.9% or 100% identical to SEQID NO: 14, preferably 98%, 99% or 100% identical to SEQ ID NO: 14. Inparticular embodiments of the application, the vector comprises a codingsequence for the fusion having SEQ ID NO: 1 operably linked to SEQ IDNO: 14, which is further operably linked to SEQ ID NO: 3.

The polynucleotides and expression vectors encoding the HBV antigens ofthe application can be made by any method known in the art in view ofthe present disclosure. For example, a polynucleotide encoding an HBVantigen can be introduced or “cloned” into an expression vector usingstandard molecular biology techniques, e.g., polymerase chain reaction(PCR), etc., which are well known to those skilled in the art.

Adenoviruses

In an aspect, the application provides a recombinant adenoviruscomprising a heterologous nucleotide sequence encoding an antigenic HBVcore antigen. In another aspect, the application provides a adenoviruscomprising a heterologous nucleotide sequence encoding an antigenic HBVpol antigen. In another, the application provides a recombinantadenovirus vector comprising a first heterologous nucleotide sequenceencoding an antigenic HBV core antigen and a second heterologousnucleotide sequence encoding an antigenic HBV pol antigen. In anotheraspect, the application provides a recombinant adenovirus comprising aheterologous nucleotide sequence encoding an antigenic HBV core-HBV polfusion protein.

An adenovirus according to the application belongs to the family of theAdenoviridae and preferably is one that belongs to the genusMastadenovirus. It can be a human adenovirus, but also an adenovirusthat infects other species, including but not limited to a bovineadenovirus (e.g. bovine adenovirus 3, BAdV3), a canine adenovirus (e.g.CAdV2), a porcine adenovirus (e.g. PAdV3 or 5), or a simian adenovirus(which includes a monkey adenovirus and an ape adenovirus, such as achimpanzee adenovirus or a gorilla adenovirus). Preferably, theadenovirus is a human adenovirus (HAdV, or AdHu; in the application ahuman adenovirus is meant if referred to as Ad without indication ofspecies, e.g. the brief notation “Ad5” means the same as HAdV5, which ishuman adenovirus serotype 5), or a simian adenovirus such as chimpanzeeor gorilla adenovirus (ChAd, AdCh, or SAdV).

Most advanced studies have been performed using human adenoviruses, andhuman adenoviruses are preferred according to certain aspects of theapplication. In certain preferred embodiments, the recombinantadenovirus according to the application is based upon a humanadenovirus. In preferred embodiments, the recombinant adenovirus isbased upon a human adenovirus serotype 5, 11, 26, 34, 35, 48, 49 or 50.According to a particularly preferred embodiment of the application, anadenovirus is a human adenovirus of one of the serotypes 26 or 35.

An advantage of these serotypes is a low seroprevalence and/or lowpre-existing neutralizing antibody titers in the human population.Preparation of rAd26 vectors is described, for example, in WO2007/104792 and in Abbink et al., (2007) Virol 81(9): 4654-63, both ofwhich are incorporated by reference herein in their entirety. Exemplarygenome sequences of Ad26 are found in GenBank Accession EF 153474 and inWO2007/104792 (see, e.g., SEQ ID NO:1). Preparation of rAd35 vectors isdescribed, for example, in U.S. Pat. No. 7,270,811, in WO00/70071, andin Vogels et al., (2003) J Virol 77(15): 8263-71, all of which areincorporated by reference herein in their entirety. Exemplary genomesequences of Ad35 are found in GenBank Accession AC_000019 and inWO00/70071 (see, e.g., FIG. 6).

Simian adenoviruses generally also have a low seroprevalence and/or lowpre-existing neutralizing antibody titers in the human population, and asignificant amount of work has been reported using chimpanzee adenovirusvectors (e.g. U.S. Pat. No. 6,083,716; WO2005/071093; WO 2010/086189; WO2010085984; Farina et al, 2001, J Virol 75: 11603-13; Cohen et al, 2002,J Gen Virol 83: 151-55; Kobinger et al, 2006, Virology 346: 394-401;Tatsis et al., 2007, Molecular Therapy 15: 608-17; see also review byBangari and Mittal, 2006, Vaccine 24: 849-62; and review by Lasaro andErtl, 2009, Mol Ther 17: 1333-39). Hence, in other preferredembodiments, the recombinant adenovirus according to the application isbased upon a simian adenovirus, e.g. a chimpanzee adenovirus. In anembodiment of the application, the recombinant adenovirus is based uponsimian adenovirus type 1, 3, 7, 8, 21, 22, 23, 24, 25, 26, 27.1, 28.1,29, 30, 31.1, 32, 33, 34, 35.1, 36, 37.2, 39, 40.1, 41.1, 42.1, 43, 44,45, 46, 48, 49, 50 or SA7P.

Adenoviral Vectors rAd26 and rAd35

In a preferred embodiment of the application, the adenoviral vectorscomprise capsid proteins from two rare serotypes: Ad26 and Ad35. In thetypical embodiment, the vector is an rAd26 or rAd35 virus.

Thus, the vectors that can be used in the application comprise an Ad26or Ad35 capsid protein (e.g., a fiber, penton or hexon protein). One ofskill will recognize that it is not necessary that an entire Ad26 orAd35 capsid protein be used in the vectors of the application. Thus,chimeric capsid proteins that include at least a part of an Ad26 or Ad35capsid protein can be used in the vectors of the application. Thevectors of the application may also comprise capsid proteins in whichthe fiber, penton, and hexon proteins are each derived from a differentserotype, so long as at least one capsid protein is derived from Ad26 orAd35. In preferred embodiments, the fiber, penton and hexon proteins areeach derived from Ad26 or each from Ad35.

One of skill will recognize that elements derived from multipleserotypes can be combined in a single recombinant adenovirus vector.Thus, a chimeric adenovirus that combines desirable properties fromdifferent serotypes can be produced. Thus, in some embodiments, achimeric adenovirus of the application could combine the absence ofpre-existing immunity of the Ad26 and Ad35 serotypes withcharacteristics such as temperature stability, assembly, anchoring,production yield, redirected or improved infection, stability of the DNAin the target cell, and the like.

In an embodiment of the application the recombinant adenovirus vectoruseful in the application is derived mainly or entirely from Ad35 orfrom Ad26 (i.e., the vector is rAd35 or rAd26). In some embodiments, theadenovirus is replication deficient, e.g. because it contains a deletionin the E1 region of the genome. For the adenoviruses of the application,being derived from Ad26 or Ad35, it is typical to exchange the E4-orf6coding sequence of the adenovirus with the E4-orf6 of an adenovirus ofhuman subgroup C, such as Ad5. This allows propagation of suchadenoviruses in well-known complementing cell lines that express the E1genes of Ad5, such as for example 293 cells, PER.C6 cells, and the like(see, e.g. Havenga et al, 2006, J Gen Virol 87: 2135-43; WO 03/104467).In an embodiment of the application, the adenovirus is a humanadenovirus of serotype 35, with a deletion in the E1 region into whichthe nucleic acid encoding the antigen has been cloned, and with an E4orf6 region of Ad5. In an embodiment of the application, the adenovirusis a human adenovirus of serotype 26, with a deletion in the E1 regioninto which the nucleic acid encoding the antigen has been cloned, andwith an E4 orf6 region of Ad5. For the Ad35 adenovirus, it is typical toretain the 3′ end of the E1B 55K open reading frame in the adenovirus,for instance the 166 bp directly upstream of the pIX open reading frameor a fragment comprising this such as a 243 bp fragment directlyupstream of the pIX start codon, marked at the 5′ end by a Bsu36Irestriction site, since this increases the stability of the adenovirusbecause the promoter of the pIX gene is partly residing in this area(see, e.g. Havenga et al, 2006, supra; WO 2004/001032).

The preparation of recombinant adenoviral vectors is well known in theart. Preparation of rAd26 vectors is described, for example, in WO2007/104792 and in Abbink et al., (2007) Virol 81(9): 4654-63. Exemplarygenome sequences of Ad26 are found in GenBank Accession EF 153474 and inSEQ ID NO:1 of WO 2007/104792. Preparation of rAd35 vectors isdescribed, for example, in U.S. Pat. No. 7,270,811 and in Vogels et al.,(2003) J Virol 77(15): 8263-71. An exemplary genome sequence of Ad35 isfound in GenBank Accession AC_000019.

In an embodiment of the application, the vectors useful in theapplication include those described in WO2012/082918, the disclosure ofwhich is incorporated herein by reference in its entirety.

Typically, a vector useful in the application is produced using anucleic acid comprising the entire recombinant adenoviral genome (e.g.,a plasmid, cosmid, or baculovirus vector). Thus, the application alsoprovides isolated nucleic acid molecules that encode the adenoviralvectors of the application. The nucleic acid molecules of theapplication may be in the form of RNA or in the form of DNA obtained bycloning or produced synthetically. The DNA may be double-stranded orsingle-stranded.

The adenovirus vectors useful in the application are typicallyreplication defective. In these embodiments, the virus is renderedreplication-defective by deletion or inactivation of regions critical toreplication of the virus, such as the E1 region. The regions can besubstantially deleted or inactivated by, for example, inserting the geneof interest (usually linked to a promoter). In some embodiments, thevectors of the application may contain deletions in other regions, suchas the E2, E3 or E4 regions or insertions of heterologous genes linkedto a promoter. For E2- and/or E4-mutated adenoviruses, generally E2-and/or E4-complementing cell lines are used to generate recombinantadenoviruses. Mutations in the E3 region of the adenovirus need not becomplemented by the cell line, since E3 is not required for replication.

A packaging cell line is typically used to produce sufficient amount ofadenovirus vectors of the application. A packaging cell is a cell thatcomprises those genes that have been deleted or inactivated in areplication-defective vector, thus allowing the virus to replicate inthe cell. Suitable cell lines include, for example, PER.C6, 911, 293,and E1 A549.

As noted above, a wide variety of Hepatitis B virus (HBV) antigens(e.g., HBV core and HBV polymerase antigens) can be expressed in thevectors. If required, the heterologous gene encoding the HBV antigen canbe codon-optimized to ensure proper expression in the treated host(e.g., human). Codon-optimization is a technology widely applied in theart. Typically, the heterologous gene is cloned into the E1 and/or theE3 region of the adenoviral genome.

The heterologous Hepatitis B virus gene may be under the control of(i.e., operably linked to) an adenovirus-derived promoter (e.g., theMajor Late Promoter) or may be under the control of a heterologouspromoter. Examples of suitable heterologous promoters include the CMVpromoter and the RSV promoter. Preferably, the promoter is locatedupstream of the heterologous gene of interest within an expressioncassette.

MVA Vectors

MVA vectors useful for the application utilize attenuated virus derivedfrom Modified Vaccinia Ankara virus. The MVA vectors express a widevariety of HBV antigens (e.g., HBV core and HBV polymerase antigens). Inan aspect, the application provides a recombinant MVA vector comprisinga heterologous nucleotide sequence encoding an antigenic HBV coreantigen. In another aspect, the application provides a recombinant MVAvector comprising a heterologous nucleotide sequence encoding anantigenic HBV pol antigen. In an aspect, the application provides arecombinant MVA vector comprising a first heterologous nucleotidesequence encoding an antigenic HBV core antigen and a secondheterologous nucleotide sequence encoding an antigenic HBV pol antigen.In another aspect, the application provides a recombinant MVA vectorcomprising a heterologous nucleotide sequence encoding an antigenic HBVcore-HBV pol fusion protein.

Modified Vaccinia Virus Ankara (“MVA”)

The man-made attenuated modified vaccinia virus Ankara (“MVA”) wasgenerated by 516 serial passages on chicken embryo fibroblasts of theAnkara strain of vaccinia virus (CVA) (for review see Mayr, A., et al.Infection 3, 6-14 (1975)). As a consequence of these long-term passages,the genome of the resulting MVA virus had about 31 kilobases of itsgenomic sequence deleted and, therefore, was described as highly hostcell restricted for replication to avian cells (Meyer, H. et al., J.Gen. Virol. 72, 1031-1038 (1991)). It was shown in a variety of animalmodels that the resulting MVA was significantly avirulent compared tothe fully replication competent starting material (Mayr, A. & Danner,K., Dev. Biol. Stand. 41: 225-34 (1978)).

An MVA virus useful in the practice of the application can include, butis not limited to, MVA-572 (deposited as ECACC V94012707 on Jan. 27,1994); MVA-575 (deposited as ECACC V00120707 on Dec. 7, 2000), MVA-1721(referenced in Suter et al., Vaccine 2009), and ACAM3000 (deposited asATCC® PTA-5095 on Mar. 27, 2003).

More preferably the MVA used in accordance with the application includesMVA-BN and derivatives of MVA-BN. MVA-BN has been described inInternational PCT publication WO 02/042480. “Derivatives” of MVA-BNrefer to viruses exhibiting essentially the same replicationcharacteristics as MVA-BN, as described herein, but exhibitingdifferences in one or more parts of their genomes.

MVA-BN, as well as derivatives thereof, is replication incompetent,meaning a failure to reproductively replicate in vivo and in vitro. Morespecifically in vitro, MVA-BN or derivatives thereof have been describedas being capable of reproductive replication in chicken embryofibroblasts (CEF), but not capable of reproductive replication in thehuman keratinocyte cell line HaCat (Boukamp et al (1988), J. Cell Biol.106:761-771), the human bone osteosarcoma cell line 143B (ECACC DepositNo. 91112502), the human embryo kidney cell line 293 (ECACC Deposit No.85120602), and the human cervix adenocarcinoma cell line HeLa (ATCCDeposit No. CCL-2). Additionally, MVA-BN or derivatives thereof have avirus amplification ratio at least two fold less, more preferablythree-fold less than MVA-575 in Hela cells and HaCaT cell lines. Testsand assay for these properties of MVA-BN and derivatives thereof aredescribed in WO 02/42480 (U.S. Patent application No. 2003/0206926) andWO 03/048184 (U.S. Patent application No. 2006/0159699).

The term “not capable of reproductive replication” or “no capability ofreproductive replication” in human cell lines in vitro as described inthe previous paragraphs is, for example, described in WO 02/42480, whichalso teaches how to obtain MVA having the desired properties asmentioned above. The term applies to a virus that has a virusamplification ratio in vitro at 4 days after infection of less than 1using the assays described in WO 02/42480 or in U.S. Pat. No. 6,761,893.

The term “failure to reproductively replicate” refers to a virus thathas a virus amplification ratio in human cell lines in vitro asdescribed in the previous paragraphs at 4 days after infection of lessthan 1. Assays described in WO 02/42480 or in U.S. Pat. No. 6,761,893are applicable for the determination of the virus amplification ratio.

The amplification or replication of a virus in human cell lines in vitroas described in the previous paragraphs is normally expressed as theratio of virus produced from an infected cell (output) to the amountoriginally used to infect the cell in the first place (input) referredto as the “amplification ratio”. An amplification ratio of “1” definesan amplification status where the amount of virus produced from theinfected cells is the same as the amount initially used to infect thecells, meaning that the infected cells are permissive for virusinfection and reproduction. In contrast, an amplification ratio of lessthan 1, i.e., a decrease in output compared to the input level,indicates a lack of reproductive replication and therefore attenuationof the virus.

The advantages of MVA-based vaccine include their safety profile as wellas availability for large scale vaccine production. Preclinical testshave revealed that MVA-BN demonstrates superior attenuation and efficacycompared to other MVA strains (WO 02/42480). An additional property ofMVA-BN strains is the ability to induce substantially the same level ofimmunity in vaccinia virus prime/vaccinia virus boost regimes whencompared to DNA-prime/vaccinia virus boost regimes.

The recombinant MVA-BN viruses, the most preferred embodiment herein,are considered to be safe because of their distinct replicationdeficiency in mammalian cells and their well-established avirulence.Furthermore, in addition to its efficacy, the feasibility of industrialscale manufacturing can be beneficial. Additionally, MVA-based vaccinescan deliver multiple heterologous antigens and allow for simultaneousinduction of humoral and cellular immunity.

MVA vectors useful for the application can be prepared using methodsknown in the art, such as those described in WO/2002/042480 andWO/2002/24224, the relevant disclosures of which are incorporated hereinby references.

In a preferred embodiment of the application, the MVA vector(s) comprisea nucleic acid that encodes one or more antigenic proteins selected fromthe group consisting of HBV core antigen, HBV pol antigen, and a HBVcore-HBV pol fusion antigen.

The HBV antigen protein may be inserted into one or more intergenicregions (IGR) of the MVA. In an embodiment of the application, the IGRis selected from IGR07/08, IGR 44/45, IGR 64/65, IGR 88/89, IGR 136/137,and IGR 148/149. In an embodiment of the application, less than 5, 4, 3,or 2 IGRs of the recombinant MVA comprise heterologous nucleotidesequences encoding antigenic determinants of a HBV core antigen and/or aHBV pol antigen. The heterologous nucleotide sequences may, additionallyor alternatively, be inserted into one or more of the naturallyoccurring deletion sites, in particular into the main deletion sites I,II, III, IV, V, or VI of the MVA genome. In an embodiment of theapplication, less than 5, 4, 3, or 2 of the naturally occurring deletionsites of the recombinant MVA comprise heterologous nucleotide sequencesencoding antigenic determinants of a HBV core antigen and/or a HBV polantigen.

The number of insertion sites of MVA comprising heterologous nucleotidesequences encoding antigenic determinants of a HBV protein can be 1, 2,3, 4, 5, 6, 7, or more. In an embodiment of the application, theheterologous nucleotide sequences are inserted into 4, 3, 2, or fewerinsertion sites. Preferably, two insertion sites are used. In anembodiment of the application, three insertion sites are used.Preferably, the recombinant MVA comprises at least 2, 3, 4, 5, 6, or 7genes inserted into 2 or 3 insertion sites.

The recombinant MVA viruses provided herein can be generated by routinemethods known in the art. Methods to obtain recombinant poxviruses or toinsert exogenous coding sequences into a poxviral genome are well knownto the person skilled in the art. For example, methods for standardmolecular biology techniques such as cloning of DNA, DNA and RNAisolation, Western blot analysis, RT-PCR and PCR amplificationtechniques are described in Molecular Cloning, A laboratory Manual (2ndEd.) (J. Sambrook et al., Cold Spring Harbor Laboratory Press (1989)),and techniques for the handling and manipulation of viruses aredescribed in Virology Methods Manual (B. W. J. Mahy et al. (eds.),Academic Press (1996)). Similarly, techniques and know-how for thehandling, manipulation and genetic engineering of MVA are described inMolecular Virology: A Practical Approach (A. J. Davison & R. M. Elliott(Eds.), The Practical Approach Series, IRL Press at Oxford UniversityPress, Oxford, UK (1993)(see, e.g., Chapter 9: Expression of genes byVaccinia virus vectors)) and Current Protocols in Molecular Biology(John Wiley & Son, Inc. (1998)(see, e.g., Chapter 16, Section IV:Expression of proteins in mammalian cells using vaccinia viral vector)).

For the generation of the various recombinant MVAs disclosed herein,different methods may be applicable. The DNA sequence to be insertedinto the virus can be placed into an E. coli plasmid construct intowhich DNA homologous to a section of DNA of the MVA has been inserted.Separately, the DNA sequence to be inserted can be ligated to apromoter. The promoter-gene linkage can be positioned in the plasmidconstruct so that the promoter-gene linkage is flanked on both ends byDNA homologous to a DNA sequence flanking a region of MVA DNA containinga non-essential locus. The resulting plasmid construct can be amplifiedby propagation within E. coli bacteria and isolated. The isolatedplasmid containing the DNA gene sequence to be inserted can betransfected into a cell culture, e.g., of chicken embryo fibroblasts(CEFs), at the same time the culture is infected with MVA. Recombinationbetween homologous MVA DNA in the plasmid and the viral genome,respectively, can generate an MVA modified by the presence of foreignDNA sequences.

According to a preferred embodiment, a cell of a suitable cell cultureas, e.g., CEF cells, can be infected with a poxvirus. The infected cellcan be, subsequently, transfected with a first plasmid vector comprisinga foreign or heterologous gene or genes, preferably under thetranscriptional control of a poxvirus expression control element. Asexplained above, the plasmid vector also comprises sequences capable ofdirecting the insertion of the exogenous sequence into a selected partof the poxviral genome. Optionally, the plasmid vector also contains acassette comprising a marker and/or selection gene operably linked to apoxviral promoter.

Suitable marker or selection genes are, e.g., the genes encoding thegreen fluorescent protein, β-galactosidase,neomycin-phosphoribosyltransferase or other markers. The use ofselection or marker cassettes simplifies the identification andisolation of the generated recombinant poxvirus. However, a recombinantpoxvirus can also be identified by PCR technology. Subsequently, afurther cell can be infected with the recombinant poxvirus obtained asdescribed above and transfected with a second vector comprising a secondforeign or heterologous gene or genes. In case, this gene shall beintroduced into a different insertion site of the poxviral genome, thesecond vector also differs in the poxvirus-homologous sequencesdirecting the integration of the second foreign gene or genes into thegenome of the poxvirus. After homologous recombination has occurred, therecombinant virus comprising two or more foreign or heterologous genescan be isolated. For introducing additional foreign genes into therecombinant virus, the steps of infection and transfection can berepeated by using the recombinant virus isolated in previous steps forinfection and by using a further vector comprising a further foreigngene or genes for transfection.

Alternatively, the steps of infection and transfection as describedabove are interchangeable, i.e., a suitable cell can at first betransfected by the plasmid vector comprising the foreign gene and, then,infected with the poxvirus. As a further alternative, it is alsopossible to introduce each foreign gene into different viruses,co-infect a cell with all the obtained recombinant viruses and screenfor a recombinant including all foreign genes. A third alternative isligation of DNA genome and foreign sequences in vitro and reconstitutionof the recombined vaccinia virus DNA genome using a helper virus. Afourth alternative is homologous recombination in E. coli or anotherbacterial species between a vaccinia virus genome, such as MVA, clonedas a bacterial artificial chromosome (BAC) and a linear foreign sequenceflanked with DNA sequences homologous to sequences flanking the desiredsite of integration in the vaccinia virus genome.

The heterologous HBV gene (e.g., a HBV core antigen, a HBV pol antigen,and/or a HBV core-HBV-pol fusion protein) may be under the control of(i.e., operably linked to) one or more poxvirus promoters. In anembodiment of the application, the poxvirus promoter is a Pr7.5promoter, a hybrid early/late promoter, or a PrS promoter, a PrS5Epromoter, a synthetic or natural early or late promoter, or a cowpoxvirus ATI promoter.

Compositions, Immunogenic Combinations, and Vaccines

The application also relates to compositions, immunogenic combinations,more particularly kits, and vaccines comprising one or more HBVantigens, polynucleotides, and/or vectors encoding one more HBV antigensaccording to the application. Any of the HBV antigens, polynucleotides(including RNA and DNA), and/or vectors of the application describedherein can be used in the compositions, immunogenic combinations orkits, and vaccines of the application.

In a general aspect, the application provides a composition comprisingan isolated or non-naturally occurring nucleic acid molecule (DNA orRNA) encoding a truncated HBV core antigen consisting of an amino acidsequence that is at least 90% identical to SEQ ID NO: 2 or a HBVpolymerase antigen comprising an amino acid sequence that is at least90% identical to SEQ ID NO: 4, a vector comprising the isolated ornon-naturally occurring nucleic acid molecule, and/or an isolated ornon-naturally occurring polypeptide encoded by the isolated ornon-naturally occurring nucleic acid molecule.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring nucleic acid molecule (DNA or RNA) encoding atruncated HBV core antigen consisting of an amino acid sequence that isat least 90% identical to SEQ ID NO: 2, preferably 100% identical to SEQID NO: 2.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring nucleic acid molecule (DNA or RNA) encoding aHBV pol antigen comprising an amino acid sequence that is at least 90%identical to SEQ ID NO: 4, preferably 100% identical to SEQ ID NO: 4.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring nucleic acid molecule (DNA or RNA) comprisinga polynucleotide sequence encoding a truncated HBV core antigenconsisting of an amino acid sequence that is at least 90% identical toSEQ ID NO: 2, preferably 100% identical to SEQ ID NO: 2; and an isolatedor non-naturally occurring nucleic acid molecule (DNA or RNA) comprisinga polynucleotide sequence encoding a HBV pol antigen comprising an aminoacid sequence that is at least 90% identical to SEQ ID NO: 4, preferably100% identical to SEQ ID NO: 4. The coding sequences for the truncatedHBV core antigen and the HBV Pol antigen can be present in the sameisolated or non-naturally occurring nucleic acid molecule (DNA or RNA),or in two different isolated or non-naturally occurring nucleic acidmolecules (DNA or RNA).

In an embodiment of the application, a composition comprises a viralvector comprising a polynucleotide encoding a truncated HBV core antigenconsisting of an amino acid sequence that is at least 90% identical toSEQ ID NO: 2, preferably 100% identical to SEQ ID NO: 2.

In an embodiment of the application, a composition comprises a viralvector comprising a polynucleotide encoding a HBV pol antigen comprisingan amino acid sequence that is at least 90% identical to SEQ ID NO: 4,preferably 100% identical to SEQ ID NO: 4.

In an embodiment of the application, a composition comprises a viralvector comprising a polynucleotide encoding a truncated HBV core antigenconsisting of an amino acid sequence that is at least 90% identical toSEQ ID NO: 2, preferably 100% identical to SEQ ID NO: 2; and a viralvector comprising a polynucleotide encoding a HBV pol antigen comprisingan amino acid sequence that is at least 90% identical to SEQ ID NO: 4,preferably 100% identical to SEQ ID NO: 4. The vector comprising thecoding sequence for the truncated HBV core antigen and the vectorcomprising the coding sequence for the HBV pol antigen can be the samevector, or two different vectors.

In an embodiment of the application, a composition comprises a viralvector comprising a polynucleotide encoding a fusion protein comprisinga truncated HBV core antigen consisting of an amino acid sequence thatis at least 90% identical to SEQ ID NO: 2, preferably 100% identical toSEQ ID NO: 2, operably linked to a HBV Pol antigen comprising an aminoacid sequence that is at least 90% identical to SEQ ID NO: 4, preferably100% identical to SEQ ID NO: 4, or vice versa. Preferably, the fusionprotein further comprises a linker that operably links the truncated HBVcore antigen to the HBV Pol antigen, or vice versa. Preferably, thelinker has the amino acid sequence of (AlaGly)n, wherein n is an integerof 2 to 5.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring truncated HBV core antigen consisting of anamino acid sequence that is at least 90% identical to SEQ ID NO: 2,preferably 100% identical to SEQ ID NO: 2.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring HBV Pol antigen comprising an amino acidsequence that is at least 90% identical to SEQ ID NO: 4, preferably 100%identical to SEQ ID NO: 4.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring truncated HBV core antigen consisting of anamino acid sequence that is at least 90% identical to SEQ ID NO: 2,preferably 100% identical to SEQ ID NO: 2; and an isolated ornon-naturally occurring HBV Pol antigen comprising an amino acidsequence that is at least 90% identical to SEQ ID NO: 4, preferably 100%identical to SEQ ID NO: 4.

In an embodiment of the application, a composition comprises an isolatedor non-naturally occurring fusion protein comprising a truncated HBVcore antigen consisting of an amino acid sequence that is at least 90%identical to SEQ ID NO: 2, preferably 100% identical to SEQ ID NO: 2,operably linked to a HBV Pol antigen comprising an amino acid sequencethat is at least 90% identical to SEQ ID NO: 4, preferably 100%identical to SEQ ID NO: 4, or vice versa. Preferably, the fusion proteinfurther comprises a linker that operably links the truncated HBV coreantigen to the HBV Pol antigen, or vice versa. Preferably, the linkerhas the amino acid sequence of (AlaGly)n, wherein n is an integer of 2to 5.

In another general aspect, the application relates to an immunogeniccombination or a kit comprising polynucleotides expressing a truncatedHBV core antigen and an HBV pol antigen according to embodiments of theapplication. Any polynucleotides and/or vectors encoding HBV core andpol antigens of the application described herein can be used in theimmunogenic combinations or kits of the application.

According to embodiments of the application, the polynucleotides in avaccine combination or kit can be linked or separate, such that the HBVantigens expressed from such polynucleotides are fused together orproduced as separate proteins, whether expressed from the same ordifferent polynucleotides. In one embodiment, the first and secondpolynucleotides are present in separate viral vectors used incombination either in the same or separate compositions, such that theexpressed proteins are also separate proteins, but used in combination.In another embodiment, the HBV antigens encoded by the first and secondpolynucleotides can be expressed from the same viral vector, such thatan HBV core-pol fusion antigen is produced. Optionally, the core and polantigens can be joined or fused together by a short linker.Alternatively, the HBV antigens encoded by the first and secondpolynucleotides can be expressed independently from a single vectorusing a using a ribosomal slippage site (also known as cis-hydrolasesite) between the core and pol antigen coding sequences. This strategyresults in a bicistronic expression vector in which individual core andpol antigens are produced from a single mRNA transcript. The core andpol antigens produced from such a bicistronic expression vector can haveadditional N or C-terminal residues, depending upon the ordering of thecoding sequences on the mRNA transcript. Examples of ribosomal slippagesites that can be used for this purpose include, but are not limited to,the FA2 slippage site from foot-and-mouth disease virus (FMDV). Anotherpossibility is that the HBV antigens encoded by the first and secondpolynucleotides can be expressed independently from two separatevectors, one encoding the HBV core antigen and one encoding the HBV polantigen.

In a preferred embodiment, the first and second polynucleotides arepresent in separate viral vectors. Preferably, the separate vectors arepresent in the same composition.

In a particular embodiment of the application, an immunogeniccombination or kit comprises: a first vector, preferably a DNA plasmidor a viral vector, comprising a polynucleotide encoding a truncated HBVcore antigen consisting of an amino acid sequence that is at least 90%identical to SEQ ID NO: 2, preferably 100% identical to SEQ ID NO: 2;and a second vector, preferably a DNA plasmid or a viral vector,comprising a polynucleotide encoding a HBV polymerase antigen comprisingan amino acid sequence that is at least 98% identical to SEQ ID NO: 4,preferably 100% identical to SEQ ID NO: 4.

In one particular embodiment of the application, the first vector is afirst DNA plasmid and the second vector is a second DNA plasmid. Each ofthe first and second DNA plasmids comprises an origin of replication,preferably a pUC ORI of SEQ ID NO: 21, and an antibiotic resistancecassette, preferably comprising a codon optimized Kan^(r) (Kanamycinresistance) gene having a polynucleotide sequence that is at least 90%identical to SEQ ID NO: 22, preferably under control of a bla promoter,for instance the bla promoter shown in SEQ ID NO: 24. Each of the firstand second DNA plasmids independently further comprises at least one ofa promoter sequence, enhancer sequence, and a polynucleotide sequenceencoding a signal peptide sequence operably linked to the firstpolynucleotide sequence or the second polynucleotide sequence.Preferably, each of the first and second DNA plasmids comprises anupstream sequence operably linked to the first polynucleotide or thesecond polynucleotide, wherein the upstream sequence comprises, from 5′end to 3′ end, a promoter sequence of SEQ ID NO: 7, an enhancer sequenceof SEQ ID NO: 8, and a polynucleotide sequence encoding a signal peptidesequence having the amino acid sequence of SEQ ID NO: 6. Each of thefirst and second DNA plasmids can also comprise a polyadenylation signallocated downstream of the coding sequence of the HBV antigen, such asthe bGH polyadenylation signal of SEQ ID NO: 9.

In one particular embodiment of the application, the first vector is afirst viral vector and the second vector is a second viral vector.Preferably, each of the first and second viral vector is an adenoviralvector, more preferably an Ad26 or Ad35 vector, comprising an expressioncassette including the polynucleotide encoding the HBV pol antigen orthe truncated HBV core antigen of the application; an upstream sequenceoperably linked to the polynucleotide encoding the HBV antigencomprising, from 5′ end to 3′ end, a promoter sequence, preferably a CMVpromoter sequence of SEQ ID NO: 7, an enhancer sequence, preferably anApoA1 gene fragment sequence of SEQ ID NO: 15 or a triple enhancersequence of SEQ ID NO: 8, and a polynucleotide sequence encoding asignal peptide sequence, preferably a cystatin S signal having the aminoacid sequence of SEQ ID NO: 6 or an immunoglobulin secretion signalhaving the amino acid sequence of SEQ ID NO: 11; and a downstreamsequence operably linked to the polynucleotide encoding the HBV antigencomprising a polyadenylation signal, preferably a SV40 polyadenylationsignal of SEQ ID NO:16.

In a particular embodiment of the application, the first vector is afirst viral vector and the second vector is a second viral vector.Preferably, each of the first and second viral vector is a MVA vectorcomprising an expression cassette including the polynucleotide encodingthe HBV pol antigen and/or the truncated HBV core antigen of theapplication; an upstream sequence operably linked to the polynucleotideencoding the HBV antigen comprising, from 5′ end to 3′ end, a promotersequence, preferably a PrMVA13.5 long promoter sequence of SEQ ID NO: 25or a PrHyb promoter sequence of SEQ ID NO: 26, and a polynucleotidesequence encoding a signal peptide sequence, preferably a cystatin Ssignal having the amino acid sequence of SEQ ID NO: 6 or animmunoglobulin secretion signal having the amino acid sequence of SEQ IDNO: 11; and a downstream sequence operably linked to the polynucleotideencoding the HBV antigen comprising a polyadenylation signal or an earlytermination signal, wherein the early termination signal has anucleotide sequence of SEQ ID NO:28, or wherein the polyadenylationsignal is selected from an SV40 polyadenylation signal having apolynucleotide sequence of SEQ ID NO: 16 or a bGH polyadenylation signalhaving a polynucleotide sequence of SEQ ID NO: 9, preferably thedownstream sequence operably linked to the polynucleotide encoding theHBV antigen is an early termination signal having a nucleotide sequenceof SEQ ID NO: 28.

In an embodiment of the application, provided is a vaccine combinationcomprising (a) a first composition comprising an immunologicallyeffective amount of an adenovirus vector comprising a firstpolynucleotide sequence encoding an HBV polymerase antigen comprising anamino acid sequence that is at least 98% identical to SEQ ID NO:4,wherein the HBV polymerase antigen does not have reverse transcriptaseactivity and RNase H activity; and (b) a second composition comprisingan immunologically effective amount of a Modified Vaccinia Ankara (MVA)vector comprising a second polynucleotide sequence encoding an HBVpolymerase antigen comprising an amino acid sequence that is at least98% identical to SEQ ID NO: 4, wherein the HBV polymerase antigen doesnot have reverse transcriptase activity and RNase H activity; whereinthe first composition is administered to the human subject for primingthe immune response, and the second composition is administered to thehuman subject one or more times for boosting the immune response.

In an embodiment of the application, provided is a vaccine combinationcomprising (a) a first composition comprising an immunologicallyeffective amount of a Modified Vaccinia Ankara (MVA) vector comprising afirst polynucleotide sequence encoding an HBV polymerase antigencomprising an amino acid sequence that is at least 98% identical to SEQID NO:4, wherein the HBV polymerase antigen does not have reversetranscriptase activity and RNase H activity; and (b) a secondcomposition comprising an immunologically effective amount of anadenovirus vector comprising a second polynucleotide sequence encodingan HBV polymerase antigen comprising an amino acid sequence that is atleast 98% identical to SEQ ID NO: 4, wherein the HBV polymerase antigendoes not have reverse transcriptase activity and RNase H activity;wherein the first composition is administered to the human subject forpriming the immune response, and the second composition is administeredto the human subject one or more times for boosting the immune response.

In those embodiments of the application in which an immunogeniccombination comprises a first viral vector and a second viral vector,the amount of each of the first and second vectors is not particularlylimited. For example, the first viral vector and the second viral vectorcan be present in a ratio of 10:1 to 1:10, by weight, such as 10:1, 9:1,8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7,1:8, 1:9, or 1:10, by weight. Preferably, the first and second viralvectors are present in a ratio of 1:1, by weight.

Compositions and immunogenic combinations of the application cancomprise additional polynucleotides or vectors encoding additional HBVantigens and/or additional HBV antigens or immunogenic fragmentsthereof. However, in particular embodiments, the compositions andimmunogenic combinations of the application do not comprise certainantigens.

In a particular embodiment, a composition or immunogenic combination orkit of the application does not comprise a HBsAg or a polynucleotidesequence encoding the HBsAg.

In another particular embodiment, a composition or immunogeniccombination or kit of the application does not comprise a HBV L proteinor a polynucleotide sequence encoding the HBV L protein.

In yet another particular embodiment of the application, a compositionor immunogenic combination of the application does not comprise a HBVenvelope protein or a polynucleotide sequence encoding the HBV envelopeprotein.

Compositions and immunogenic combinations of the application can alsocomprise a pharmaceutically acceptable carrier. A pharmaceuticallyacceptable carrier is non-toxic and should not interfere with theefficacy of the active ingredient. Pharmaceutically acceptable carrierscan include one or more excipients such as binders, disintegrants,swelling agents, suspending agents, emulsifying agents, wetting agents,lubricants, flavorants, sweeteners, preservatives, dyes, solubilizersand coatings. The precise nature of the carrier or other material candepend on the route of administration, e.g., intramuscular, intradermal,subcutaneous, oral, intravenous, cutaneous, intramucosal (e.g., gut),intranasal or intraperitoneal routes. For liquid injectablepreparations, for example, suspensions and solutions, suitable carriersand additives include water, glycols, oils, alcohols, preservatives,coloring agents and the like. For solid oral preparations, for example,powders, capsules, caplets, gelcaps and tablets, suitable carriers andadditives include starches, sugars, diluents, granulating agents,lubricants, binders, disintegrating agents and the like. For nasalsprays/inhalant mixtures, the aqueous solution/suspension can comprisewater, glycols, oils, emollients, stabilizers, wetting agents,preservatives, aromatics, flavors, and the like as suitable carriers andadditives.

Compositions and immunogenic combinations of the application can beformulated in any matter suitable for administration to a subject tofacilitate administration and improve efficacy, including, but notlimited to, oral (enteral) administration and parenteral injections. Theparenteral injections include intravenous injection or infusion,subcutaneous injection, intradermal injection, and intramuscularinjection. Compositions of the application can also be formulated forother routes of administration including transmucosal, ocular, rectal,long acting implantation, sublingual administration, under the tongue,from oral mucosa bypassing the portal circulation, inhalation, orintranasal.

In a preferred embodiment of the application, compositions andimmunogenic combinations of the application are formulated for parentalinjection, preferably subcutaneous, intradermal injection, orintramuscular injection, more preferably intramuscular injection.

According to embodiments of the application, compositions andimmunogenic combinations for administration will typically comprise abuffered solution in a pharmaceutically acceptable carrier, e.g., anaqueous carrier such as buffered saline and the like, e.g., phosphatebuffered saline (PBS). The compositions and immunogenic combinations canalso contain pharmaceutically acceptable substances as required toapproximate physiological conditions such as pH adjusting and bufferingagents. In a typical embodiment, a composition or immunogeniccombination of the application comprising plasmid DNA can containphosphate buffered saline (PBS) as the pharmaceutically acceptablecarrier. The plasmid DNA can be present in a concentration of, e.g., 0.5mg/mL to 5 mg/mL, such as 0.5 mg/mL 1, mg/mL, 2 mg/mL, 3 mg/mL, 4 mg/mL,or 5 mg/mL, preferably at 1 mg/mL.

Compositions and immunogenic combinations of the application can beformulated as a vaccine (also referred to as an “immunogeniccomposition”) according to methods well known in the art. Suchcompositions can include adjuvants to enhance immune responses. Theoptimal ratios of each component in the formulation can be determined bytechniques well known to those skilled in the art in view of the presentdisclosure.

In an embodiment of the application, an adjuvant is included in acomposition or immunogenic combination of the application, orco-administered with a composition or immunogenic combination of theapplication. Use of an adjuvant is optional, and may further enhanceimmune responses when the composition is used for vaccination purposes.Adjuvants suitable for co-administration or inclusion in compositions inaccordance with the application should preferably be ones that arepotentially safe, well tolerated and effective in humans. An adjuvantcan be a small molecule or antibody including, but not limited to,immune checkpoint inhibitors (e.g., anti-PD1, anti-RIM-3, etc.),toll-like receptor inhibitors, RIG-1 inhibitors, IL-15 superagonists(Altor Bioscience), mutant IRF3 and IRF7 genetic adjuvants, STINGagonists (Aduro), FLT3L genetic adjuvant, IL-12 genetic adjuvant, andIL-7-hyFc.

Embodiments of the application also relate to methods of makingcompositions and immunogenic combinations of the application. Accordingto embodiments of the application, a method of producing a compositionor immunogenic combination comprises mixing an isolated polynucleotideencoding an HBV antigen, vector, and/or polypeptide of the applicationwith one or more pharmaceutically acceptable carriers. One of ordinaryskill in the art will be familiar with conventional techniques used toprepare such compositions.

Methods of Inducing/Enhancing an Immune Response

In another general aspect, the application relates to a method ofinducing an immune response against hepatitis B virus (HBV) in a subjectin need thereof, comprising administering to the subject animmunologically effective amount of a composition or immunogeniccomposition of the application. Any of the compositions and immunogeniccombinations of the application described herein can be used in themethods of the application.

The application provides an improved method of priming and boosting animmune response to a HBV antigenic protein or immunogenic polypeptidethereof in a human subject using an MVA vector in combination with anadenoviral vector.

According to a general aspect of the application, a method of enhancingan immune response in a human subject comprises:

-   -   (a) administering to the human subject a first composition        comprising an immunologically effective amount of an adenovirus        vector of the application; and    -   (b) administering to the human subject a second composition        comprising an immunologically effective amount of a MVA vector        of the application;    -   to thereby obtain an enhanced immune response against the HBV        antigen in the human subject.

According to another general aspect of the application, a method ofenhancing an immune response in a human subject comprises:

-   -   (a) administering to the human subject a first composition        comprising an immunologically effective amount of a MVA vector        of the application; and    -   (b) administering to the human subject a second composition        comprising an immunologically effective amount of an adenovirus        vector of the application;    -   to thereby obtain an enhanced immune response against the HBV        antigen in the human subject.

According to another general aspect of the application, a method ofenhancing an immune response in a human subject comprises:

-   -   (a) administering to the human subject a first composition        comprising an immunologically effective amount of a first        plasmid comprising a first non-naturally occurring nucleic acid        comprising a first polynucleotide sequence encoding an HBV pol        antigen of the application, and an immunologically effective        amount of a second plasmid comprising a second non-naturally        occurring nucleic acid comprising a second polynucleotide        sequence encoding a truncated HBV core antigen of the        application; and    -   (b) administering to the human subject a second composition        comprising an immunologically effective amount of a MVA vector        of the application;    -   to thereby obtain an enhanced immune response against the HBV        antigen in the human subject.

According to another general aspect of the application, a method ofenhancing an immune response in a human subject comprises:

-   -   (a) administering to the human subject a first composition        comprising an immunologically effective amount of a MVA vector        of the application; and    -   (b) administering to the human subject a second composition        comprising an immunologically effective amount of a first        plasmid comprising a first non-naturally occurring nucleic acid        comprising a first polynucleotide sequence encoding an HBV pol        antigen of the application, and an immunologically effective        amount of a second plasmid comprising a second non-naturally        occurring nucleic acid comprising a second polynucleotide        sequence encoding a truncated HBV core antigen of the        application;    -   to thereby obtain an enhanced immune response against the HBV        antigen in the human subject.

The first composition is administered to the human subject in needthereof to prime the immune response, and the second composition isadministered to the human subject in need thereof to boost the immuneresponse. Priming and boosting the immune response can, for example,enhance the immune response.

According to embodiments of the application, the enhanced immuneresponse comprises an enhanced antibody response against the HBVantigenic protein in the human subject.

Preferably, the enhanced immune response further comprises an enhancedCD4+ response or an enhanced CD8+ T cell response against the HBVantigenic protein in the human subject. The enhanced CD4+ T cellresponse generated by a method according to an embodiment of theapplication can be, for example, an increase or induction of a dominantCD4+ T cell response against the HBV antigenic protein, and/or anincrease or induction of polyfunctional CD4+ T cells specific to the HBVantigenic protein in the human subject. The polyfunctional CD4+ T cellsexpress more than one cytokine, such as two or more of IFN-gamma, IL-2and TNF-alpha. The enhanced CD8+ T cell response generated by a methodaccording to an embodiment of the application can be, for example, anincrease or induction of polyfunctional CD8+ T cells specific to the HBVantigenic protein in the human subject.

More preferably, the enhanced immune response resulting from a methodaccording to an embodiment of the application comprises an enhanced CD4+T cell response, an enhanced antibody response and an enhanced CD8+ Tcell response, against the HBV antigenic protein in the human subject.

As used herein, the term “infection” refers to the invasion of a host bya disease causing agent. A disease causing agent is considered to be“infectious” when it is capable of invading a host, and replicating orpropagating within the host. Examples of infectious agents includeviruses, e.g., HBV and certain species of adenovirus, prions, bacteria,fungi, protozoa and the like. “HBV infection” specifically refers toinvasion of a host organism, such as cells and tissues of the hostorganism, by HBV.

According to embodiments of the application, “inducing an immuneresponse” when used with reference to the methods described hereinencompasses causing a desired immune response or effect in a subject inneed thereof against HBV or an HBV infection. “Inducing an immuneresponse” also encompasses providing a therapeutic immunity for treatingagainst a pathogenic agent, i.e., HBV. As used herein, the term“therapeutic immunity” or “therapeutic immune response” means that theHBV-infected vaccinated subject is able to control an infection with thepathogenic agent, i.e., HBV, against which the vaccination was done. Inone embodiment, “inducing an immune response” means producing animmunity in a subject in need thereof, e.g., to provide a therapeuticeffect against a disease, such as HBV infection. In an embodiment of theapplication, “inducing an immune response” refers to causing orimproving cellular immunity, e.g., T cell response, against HBV. In anembodiment of the application, “inducing an immune response” refers tocausing or improving a humoral immune response against HBV. In anembodiment of the application, “inducing an immune response” refers tocausing or improving a cellular and a humoral immune response againstHBV.

Typically, the administration of compositions and immunogeniccombinations according to embodiments of the application will have atherapeutic aim to generate an immune response against HBV after HBVinfection or development of symptoms characteristic of HBV infection,i.e., for therapeutic vaccination.

As used herein, “an immunogenically effective amount” or“immunologically effective amount” means an amount of a composition,polynucleotide, vector, or antigen sufficient to induce a desired immuneeffect or immune response in a subject in need thereof. In oneembodiment, an immunologically effective amount means an amountsufficient to induce an immune response in a subject in need thereof. Inanother embodiment, an immunologically effective amount means an amountsufficient to produce immunity in a subject in need thereof, e.g.,provide a therapeutic effect against a disease such as HBV infection. Animmunologically effective amount can vary depending upon a variety offactors, such as the physical condition of the subject, age, weight,health, etc.; the particular application, e.g., providing protectiveimmunity or therapeutic immunity; and the particular disease, e.g.,viral infection, for which immunity is desired. An immunologicallyeffective amount can readily be determined by one of ordinary skill inthe art in view of the present disclosure.

In particular embodiments of the application, an immunologicallyeffective amount refers to the amount of a composition or immunogeniccombination which is sufficient to achieve one, two, three, four, ormore of the following effects: (i) reduce or ameliorate the severity ofan HBV infection or a symptom associated therewith; (ii) reduce theduration of an HBV infection or symptom associated therewith; (iii)prevent the progression of an HBV infection or symptom associatedtherewith; (iv) cause regression of an HBV infection or symptomassociated therewith; (v) prevent the development or onset of an HBVinfection, or symptom associated therewith; (vi) prevent the recurrenceof an HBV infection or symptom associated therewith; (vii) reducehospitalization of a subject having an HBV infection; (viii) reducehospitalization length of a subject having an HBV infection; (ix)increase the survival of a subject with an HBV infection; (x) eliminatean HBV infection in a subject; (xi) inhibit or reduce HBV replication ina subject; and/or (xii) enhance or improve the prophylactic ortherapeutic effect(s) of another therapy.

In other particular embodiments, an immunologically effective amount isan amount sufficient to reduce HBsAg levels consistent with evolution toclinical seroconversion; achieve sustained HBsAg clearance associatedwith reduction of infected hepatocytes by a subject's immune system;induce HBV-antigen specific activated T-cell populations; and/or achievepersistent loss of HBsAg within 12 months. Examples of a target indexinclude lower HBsAg below a threshold of 500 copies of HBsAg IU and/orhigher CD8 counts.

As general guidance, an immunologically effective amount when used withreference to a viral vector can range from about 1×10⁷ viral particlesper dose to about 1×10¹² viral particles per dose. An immunologicallyeffective amount can be about 1×10¹⁰, about 2×10¹⁰, about 3×10¹⁰, about4×10¹⁰, about 5×10¹⁰, about 6×10¹⁰, about 7×10¹⁰, about 8×10¹⁰, about9×10¹⁰, about 1×10¹¹, about 2×10¹¹, about 3×10¹¹, about 4×10¹¹, about5×10¹¹, or about 1×10¹² viral particles per dose. An immunologicallyeffective amount can be from one vector or from multiple vectors. Animmunologically effective amount can be administered in a singlecomposition, or in multiple compositions, such as 1, 2, 3, 4, 5, 6, 7,8, 9, or 10 compositions (e.g., tablets, capsules or injectables),wherein the administration of the multiple capsules or injectionscollectively provides a subject with an immunologically effectiveamount. It is also possible to administer an immunologically effectiveamount to a subject, and subsequently administer another dose of animmunologically effective amount to the same subject, in a so-calledprime-boost regimen. This general concept of a prime-boost regimen iswell known to the skilled person in the vaccine field. Further boosteradministrations can optionally be added to the regimen, as needed.

According to embodiments of the application, an immunogenic combinationcomprising two viral vectors, e.g., a first viral vector encoding an HBVcore antigen and second viral vector encoding an HBV pol antigen can beadministered to a subject by mixing both viral vectors and deliveringthe mixture to a single anatomic site. Alternatively, two separateimmunizations each delivering a single expression vector can beperformed. In such embodiments, whether both viral vectors areadministered in a single immunization as a mixture of in two separateimmunizations, the first viral vector and the second viral vector can beadministered in a ratio of 10:1 to 1:10, by weight, such as 10:1, 9:1,8:1, 7:1, 6:1, 5:1, 4:1, 3:1, 2:1, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7,1:8, 1:9, or 1:10, by weight. Preferably, the first and second viralvectors are administered in a ratio of 1:1, by weight.

In some embodiments, a subject to be treated according to the methods ofthe application is an HBV-infected subject, particular a subject havingchronic HBV infection. Acute HBV infection is characterized by anefficient activation of the innate immune system complemented with asubsequent broad adaptive response (e.g., HBV-specific T-cells,neutralizing antibodies), which usually results in successfulsuppression of replication or removal of infected hepatocytes. Incontrast, such responses are impaired or diminished due to high viraland antigen load, e.g., HBV envelope proteins are produced in abundanceand can be released in sub-viral particles in 1,000-fold excess toinfectious virus.

Chronic HBV infection is described in phases characterized by viralload, liver enzyme levels (necroinflammatory activity), HBeAg, or HBsAgload or presence of antibodies to these antigens. cccDNA levels stayrelatively constant at approximately 10 to 50 copies per cell, eventhough viremia can vary considerably. The persistence of the cccDNAspecies leads to chronicity. More specifically, the phases of chronicHBV infection include: (i) the immune-tolerant phase characterized byhigh viral load and normal or minimally elevated liver enzymes; (ii) theimmune activation HBeAg-positive phase in which lower or declininglevels of viral replication with significantly elevated liver enzymesare observed; (iii) the inactive HBsAg carrier phase, which is a lowreplicative state with low viral loads and normal liver enzyme levels inthe serum that may follow HBeAg seroconversion; and (iv) theHBeAg-negative phase in which viral replication occurs periodically(reactivation) with concomitant fluctuations in liver enzyme levels,mutations in the pre-core and/or basal core promoter are common, suchthat HBeAg is not produced by the infected cell.

As used herein, “chronic HBV infection” refers to a subject having thedetectable presence of HBV for more than 6 months. A subject having achronic HBV infection can be in any phase of chronic HBV infection. Inpreferred embodiments, a chronic HBV infection referred to hereinfollows the definition published by the Centers for Disease Control andPrevention (CDC), according to which a chronic HBV infection ischaracterized by the following laboratory criteria: (i) negative for IgMantibodies to hepatitis B core antigen (IgM anti-HBc) and positive forhepatitis B surface antigen (HBsAg), hepatitis B e antigen (HBeAg), ornucleic acid test for hepatitis B virus DNA, or (ii) positive for HBsAgor nucleic acid test for HBV DNA, or positive for HBeAg two times atleast 6 months apart.

According to particular embodiments, an immunogenically effective amountrefers to the amount of a composition or immunogenic combination whichis sufficient to treat chronic HBV infection.

In some embodiments, a subject having chronic HBV infection isundergoing nucleoside analog (NUC) treatment, and is NUC-suppressed. Asused herein, “NUC-suppressed” refers to a subject having an undetectableviral level of HBV and stable alanine aminotransferase (ALT) levels forat least six months. Examples of nucleoside/nucleotide analog treatmentinclude HBV polymerase inhibitors, such as entacavir and tenofovir.Preferably, a subject having chronic HBV infection does not haveadvanced hepatic fibrosis or cirrhosis. Such subject would typicallyhave a METAVIR score of less than 3 and a fibroscan result of less than9 kPa. The METAVIR score is a scoring system that is commonly used toassess the extent of inflammation and fibrosis by histopathologicalevaluation in a liver biopsy of patients with hepatitis B. The scoringsystem assigns two standardized numbers: one reflecting the degree ofinflammation and one reflecting the degree of fibrosis.

It is believed that elimination or reduction of chronic HBV may allowearly disease interception of severe liver disease, includingvirus-induced cirrhosis and hepatocellular carcinoma. Thus, the methodsof the application can also be used as therapy to treat HBV-induceddiseases. Examples of HBV-induced diseases include, but are not limitedto cirrhosis, cancer (e.g., hepatocellular carcinoma), and fibrosis,particularly advanced fibrosis characterized by a METAVIR score of 3 orhigher. In such embodiments, an immunogenically effective amount is anamount sufficient to achieve persistent loss of HBsAg within 12 monthsand significant decrease in clinical disease (e.g., cirrhosis,hepatocellular carcinoma, etc.).

Methods according to embodiments of the application further compriseadministering to the subject in need thereof another immunogenic agent(such as another HBV antigen or other antigen) or another anti-HBV agent(such as a nucleoside analog or other anti-HBV agent) in combinationwith a composition of the application.

Methods of Delivery

Compositions and immunogenic combinations of the application can beadministered to a subject by any method known in the art in view of thepresent disclosure, including, but not limited to, parenteraladministration (e.g., intramuscular, subcutaneous, intravenous, orintradermal injection), oral administration, transdermal administration,and nasal administration. Preferably, compositions and immunogeniccombinations are administered parenterally (e.g., by intramuscularinjection or intradermal injection) or transdermally.

In some embodiments of the application in which a composition orimmunogenic combination comprises one or more viral vectors,administration can be by injection through the skin, e.g., intramuscularor intradermal injection, preferably intramuscular injection.Intramuscular injection can be combined with electroporation, i.e.,application of an electric field to facilitate delivery of the DNAplasmids to cells. As used herein, the term “electroporation” refers tothe use of a transmembrane electric field pulse to induce microscopicpathways (pores) in a bio-membrane. During in vivo electroporation,electrical fields of appropriate magnitude and duration are applied tocells, inducing a transient state of enhanced cell membranepermeability, thus enabling the cellular uptake of molecules unable tocross cell membranes on their own. Creation of such pores byelectroporation facilitates passage of biomolecules, such as plasmids,oligonucleotides, siRNAs, drugs, etc., from one side of a cellularmembrane to the other. In vivo electroporation for the delivery of DNAvaccines has been shown to significantly increase plasmid uptake by hostcells, while also leading to mild-to-moderate inflammation at theinjection site. As a result, transfection efficiency and immune responseare significantly improved (e.g., up to 1,000 fold and 100 foldrespectively) with intradermal or intramuscular electroporation, incomparison to conventional injection.

In a typical embodiment, electroporation is combined with intramuscularinjection. However, it is also possible to combine electroporation withother forms of parenteral administration, e.g., intradermal injection,subcutaneous injection, etc.

Administration of a composition, immunogenic combination or vaccine ofthe application via electroporation can be accomplished usingelectroporation devices that can be configured to deliver to a desiredtissue of a mammal a pulse of energy effective to cause reversible poresto form in cell membranes. The electroporation device can include anelectroporation component and an electrode assembly or handle assembly.The electroporation component can include one or more of the followingcomponents of electroporation devices: controller, current waveformgenerator, impedance tester, waveform logger, input element, statusreporting element, communication port, memory component, power source,and power switch. Electroporation can be accomplished using an in vivoelectroporation device. Examples of electroporation devices andelectroporation methods that can facilitate delivery of compositions andimmunogenic combinations of the application, particularly thosecomprising DNA plasmids, include CELLECTRA® (Inovio Pharmaceuticals,Blue Bell, Pa.), Elgen electroporator (Inovio Pharmaceuticals, Inc.)Tri-Grid™ delivery system (Ichor Medical Systems, Inc., San Diego,Calif. 92121) and those described in U.S. Pat. Nos. 7,664,545,8,209,006, 9,452,285, 5,273,525, 6,110,161, 6,261,281, 6,958,060, and6,939,862, 7,328,064, 6,041,252, 5,873,849, 6,278,895, 6,319,901,6,912,417, 8,187,249, 9,364,664, 9,802,035, 6,117,660, and InternationalPatent Application Publication WO2017172838, all of which are hereinincorporated by reference in their entireties. Also contemplated by theapplication for delivery of the compositions and immunogeniccombinations of the application are use of a pulsed electric field, forinstance as described in, e.g., U.S. Pat. No. 6,697,669, which is hereinincorporated by reference in its entirety.

In other embodiments of the application in which a composition orimmunogenic combination comprises one or more DNA plasmids, the methodof administration is transdermal. Transdermal administration can becombined with epidermal skin abrasion to facilitate delivery of the DNAplasmids to cells. For example, a dermatological patch can be used forepidermal skin abrasion. Upon removal of the dermatological patch, thecomposition or immunogenic combination can be deposited on the abraisedskin.

Methods of delivery are not limited to the above described embodiments,and any means for intracellular delivery can be used. Other methods ofintracellular delivery contemplated by the methods of the applicationinclude, but are not limited to, liposome encapsulation, nanoparticles,etc.

Adjuvants

In some embodiments of the application, a method of inducing an immuneresponse against HBV further comprises administering an adjuvant. Theterms “adjuvant” and “immune stimulant” are used interchangeably herein,and are defined as one or more substances that cause stimulation of theimmune system. In this context, an adjuvant is used to enhance an immuneresponse to HBV antigens and antigenic HBV polypeptides of theapplication.

According to embodiments of the application, an adjuvant can be presentin an immunogenic combination or composition of the application, oradministered in a separate composition. An adjuvant can be, e.g., asmall molecule or an antibody. Examples of adjuvants suitable for use inthe application include, but are not limited to, immune checkpointinhibitors (e.g., anti-PD1, anti-RIM-3, etc.), toll-like receptorinhibitors, RIG-1 inhibitors, IL-15 superagonists (Altor Bioscience),mutant IRF3 and IRF7 genetic adjuvants, STING agonists (Aduro), FLT3Lgenetic adjuvant, IL-12 genetic adjuvant, and IL-7-hyFc.

Compositions and immunogenic combinations of the application can also beadministered in combination with at least one other anti-HBV agent.Examples of anti-HBV agents suitable for use with the applicationinclude, but are not limited to small molecules, antibodies, and/orCAR-T therapies that function as capsid inhibitors, TLR inhibitors,cccDNA inhibitors, HBV polymerase inhibitors (e.g., entecavir andtenofovir), and/or immune checkpoint inhibitors, etc. Such anti-HBVagents can be administered with the compositions and immunogeniccombinations of the application simultaneously or sequentially.

Methods of Prime/Boost Immunization

Embodiments of the application also contemplate administering animmunologically effective amount of a composition or immunogeniccombination to a subject, and subsequently administering another dose ofan immunologically effective amount of a composition or immunogeniccombination to the same subject, in a so-called prime-boost regimenThus, in one embodiment, a composition or immunogenic combination of theapplication is a primer vaccine used for priming an immune response. Inanother embodiment, a composition or immunogenic combination of theapplication is a booster vaccine used for boosting an immune response.The priming and boosting vaccines according to embodiments of theapplication can be used in the methods of the application describedherein. This general concept of a prime-boost regimen is well known tothe skilled person in the vaccine field. Any of the compositions andimmunogenic combinations of the application described herein can be usedas priming and/or boosting vaccines for priming and/or boosting animmune response against HBV.

According to embodiments of the application, a composition orimmunogenic combination of the application can be administered at leastonce for priming immunization. The composition or immunogeniccombination can be re-administered for boosting immunization. Furtherbooster administrations of the composition or vaccine combination canoptionally be added to the regimen, as needed. An adjuvant can bepresent in a composition of the application used for boostingimmunization, present in a separate composition to be administeredtogether with the composition or immunogenic combination of theapplication for the boosting immunization, or administered on its own asthe boosting immunization. In those embodiments in which an adjuvant isincluded in the regimen, the adjuvant is preferably used for boostingimmunization.

An illustrative and non-limiting example of a prime-boost regimenincludes administering a single dose of an immunologically effectiveamount of a composition or immunogenic combination of the application toa subject to prime the immune response; and subsequently administeringanother dose of an immunologically effective amount of a composition orimmunogenic combination of the application to boost the immune response,wherein the boosting immunization is first administered about one totwelve weeks (1 to 12), about two to twelve weeks (2 to 12), about twoto ten weeks (2 to 10), about two to six weeks (2 to 6), preferablyabout four weeks after the priming immunization is initiallyadministered, preferably about eight weeks after the primingimmunization is initially administered. In an embodiment of theapplication, the boosting immunization is administered at least one weekafter the priming immunization. In an embodiment of the application, theboosting immunization is administered at least two weeks after thepriming immunization. Optionally, about 10 to 14 weeks, preferably 12weeks, after the priming immunization is initially administered, afurther boosting immunization of the composition or immunogeniccombination, or other adjuvant, is administered.

Kits

The application also provides a kit comprising an immunogeniccombination of the application. A kit can comprise the firstpolynucleotide and the second polynucleotide in separate compositions,or a kit can comprise the first polynucleotide and the secondpolynucleotide in a single composition. A kit can further comprise oneor more adjuvants or immune stimulants, and/or other anti-HBV agents.

The ability to induce or stimulate an anti-HBV immune response uponadministration in an animal or human organism can be evaluated either invitro or in vivo using a variety of assays which are standard in theart. For a general description of techniques available to evaluate theonset and activation of an immune response, see for example Coligan etal. (1992 and 1994, Current Protocols in Immunology; ed. J Wiley & SonsInc, National Institute of Health). Measurement of cellular immunity canbe performed by measurement of cytokine profiles secreted by activatedeffector cells including those derived from CD4+ and CD8+ T-cells (e.g.quantification of IL-10 or IFN gamma-producing cells by ELISPOT), bydetermination of the activation status of immune effector cells (e.g. Tcell proliferation assays by a classical [3H] thymidine uptake), byassaying for antigen-specific T lymphocytes in a sensitized subject(e.g. peptide-specific lysis in a cytotoxicity assay, etc.).

The ability to stimulate a cellular and/or a humoral response can bedetermined by antibody binding and/or competition in binding (see forexample Harlow, 1989, Antibodies, Cold Spring Harbor Press). Forexample, titers of antibodies produced in response to administration ofa composition providing an immunogen can be measured by enzyme-linkedimmunosorbent assay (ELISA). The immune responses can also be measuredby neutralizing antibody assay, where a neutralization of a virus isdefined as the loss of infectivity throughreaction/inhibition/neutralization of the virus with specific antibody.The immune response can further be measured by Antibody-DependentCellular Phagocytosis (ADCP) Assay.

EMBODIMENTS

The i application provides also the following non-limiting embodiments.

Embodiment 1 is a Modified Vaccinia Ankara (MVA) vector comprising anon-naturally occurring nucleic acid molecule comprising a firstpolynucleotide sequence encoding an HBV polymerase antigen comprising anamino acid sequence that is at least 98% identical to SEQ ID NO:4.

Embodiment 2 is the MVA vector of embodiment 1, wherein the HBVpolymerase antigen does not have reverse transcriptase activity andRNase H activity.

Embodiment 3 is the MVA vector of embodiment 1 or 2, wherein the HBVpolymerase antigen is capable of inducing an immune response in a mammalagainst at least two HBV genotypes, preferably the HBV polymeraseantigen is capable of inducing a T cell response in a mammal against atleast HBV genotypes B, C, and D, and more preferably the HBV polymeraseantigen is capable of inducing a CD8 T cell response in a human subjectagainst at least HBV genotypes A, B, C, and D.

Embodiment 4 is the MVA vector of any one of embodiments 1-3, whereinthe HBV polymerase antigen comprises the amino acid sequence of SEQ IDNO: 4.

Embodiment 5 is the MVA vector of any one of embodiments 1-4, furthercomprising a polynucleotide sequence encoding a signal sequence operablylinked to the HBV polymerase antigen.

Embodiment 6 is the MVA vector of embodiment 5, wherein the signalsequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:11, preferably the signal sequence is encoded by the polynucleotidesequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 7 is the MVA vector of any one of embodiments 1-6, whereinthe first polynucleotide sequence is at least 90% identical to SEQ IDNO: 3.

Embodiment 8 is the MVA vector of embodiment 7, wherein the firstpolynucleotide sequence comprises the polynucleotide sequence of SEQ IDNO: 3.

Embodiment 9 is the MVA vector of any one of embodiments 1-8, furthercomprising a second polynucleotide sequence encoding a truncated HBVcore antigen consisting of the amino acid sequence of SEQ ID NO: 2.

Embodiment 10 is the MVA vector of embodiment 9, wherein the secondpolynucleotide sequence is at least 90% identical to SEQ ID NO: 1.

Embodiment 11 is the MVA vector of embodiment 10, wherein the secondpolynucleotide sequence comprises the polynucleotide sequence of SEQ IDNO: 1.

Embodiment 12 is the MVA vector of any one of embodiments 9-11, whereinthe second polynucleotide sequence further comprises a polynucleotidesequence encoding a signal sequence operably linked to the truncated HBVcore antigen.

Embodiment 13 is the MVA vector of embodiment 12, wherein the signalsequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:11, preferably the signal sequence is encoded by the polynucleotidesequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 14 is the MVA vector of any one of embodiments 9-13, whereinthe first and second polynucleotide sequences encode a fusion proteincomprising the truncated HBV core antigen operably linked to the HBVpolymerase antigen.

Embodiment 15 is the MVA vector of embodiment 14, wherein the fusionprotein comprises the truncated HBV core antigen operably linked to theHBV polymerase antigen via a linker.

Embodiment 16 is the MVA vector of embodiment 15, wherein the linkercomprises the amino acid sequence of (AlaGly)n, and n is an integer of 2to 5, preferably the linker is encoded by a polynucleotide sequencecomprising SEQ ID NO: 14.

Embodiment 17 is the MVA vector of embodiment 16, wherein the fusionprotein comprises the amino acid sequence of SEQ ID NO: 12.

Embodiment 18 is the MVA vector of any one of embodiments 14-17, whereinthe fusion protein further comprises a signal sequence, preferably thesignal sequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQID NO: 11, more preferably the signal sequence is encoded by thepolynucleotide sequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 19 is the MVA vector of any one of embodiments 1-18 furthercomprising at least one promoter sequence, optionally one or moreadditional regulatory sequences, preferably the at least one promotersequence comprises the polynucleotide sequence of SEQ ID NO: 25 and/orSEQ ID NO: 26, and the additional regulatory sequence is selected fromthe group consisting of an enhancer sequence of SEQ ID NO: 8 or SEQ IDNO: 15, and a polyadenylation signal sequence of SEQ ID NO: 9 or SEQ IDNO: 16.

Embodiment 20 is the MVA vector of any one of embodiments 1-19, whereinthe non-naturally occurring nucleic acid molecule does not encode a HBVantigen selected from the group consisting of a Hepatitis B surfaceantigen (HBsAg), a HBV envelope (Env) antigen, and a HBV L proteinantigen.

Embodiment 21 is an MVA vector comprising a first non-naturallyoccurring nucleic acid molecule comprising a first polynucleotidesequence encoding an HBV polymerase antigen comprising the amino acidsequence of SEQ ID NO: 4, wherein the first polynucleotide sequencefurther encodes a signal sequence comprising the amino acid sequence ofSEQ ID NO: 6, and wherein the first polynucleotide sequence furthercomprises a promoter sequence comprising the polynucleotide sequence ofSEQ ID NO: 26, and a second non-naturally occurring nucleic acidmolecule comprising a second polynucleotide sequence encoding atruncated HBV core antigen consisting of the amino acid sequence of SEQID NO: 2, wherein the second polynucleotide sequence further encodes asignal sequence comprising the amino acid sequence of SEQ ID NO: 11, andwherein the second polynucleotide sequence further comprises a promotersequence comprising the polynucleotide sequence of SEQ ID NO: 25.

Embodiment 22 is a composition comprising the MVA vector of any one ofembodiments 1-21 and a pharmaceutically acceptable carrier.

Embodiment 23 is a method of enhancing an immune response in a humansubject, the method comprising (a) administering to the human subject afirst composition comprising an immunologically effective amount of anadenovirus vector comprising a non-naturally occurring nucleic acidmolecule comprising a first polynucleotide sequence encoding an HBVpolymerase antigen comprising an amino acid sequence that is at least98% identical to SEQ ID NO:4; and (b) administering to the human subjecta second composition comprising an immunologically effective amount ofthe MVA vector of any one of embodiments 1-21; to thereby obtain anenhanced immune response against the HBV antigen in the human subject.

Embodiment 24 is the method of embodiment 23, wherein the HBV polymeraseantigen of the first composition does not have reverse transcriptaseactivity and RNase H activity.

Embodiment 25 is the method of embodiment 23 or 24, wherein the firstcomposition is for priming the immune response and the secondcomposition is for boosting the immune response.

Embodiment 26 is the method of any one of embodiments 23-25, wherein theHBV polymerase antigen of the first composition is capable of inducingan immune response in the human subject against at least two HBVgenotypes, preferably the HBV polymerase antigen is capable of inducinga T cell response in the human subject against at least HBV genotypes B,C, and D, and more preferably the HBV polymerase antigen is capable ofinducing a CD8 T cell response in the human subject against at least HBVgenotypes A, B, C, and D.

Embodiment 27 is the method of any one of embodiments 23-26, wherein theHBV polymerase antigen of the first composition comprises the amino acidsequence of SEQ ID NO: 4.

Embodiment 28 is the method of any one of embodiments 23-27, furthercomprising a polynucleotide sequence encoding a signal sequence operablylinked to the HBV polymerase antigen of the first composition.

Embodiment 29 is the method of embodiment 28, wherein the signalsequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:11, preferably the signal sequence is encoded by the polynucleotidesequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 30 is the method of any one of embodiments 23-29, wherein thefirst polynucleotide sequence of the first composition is at least 90%identical to SEQ ID NO: 19.

Embodiment 31 is the method of embodiment 30, wherein the firstpolynucleotide sequence of the first composition comprises thepolynucleotide sequence of SEQ ID NO: 19.

Embodiment 32 is the method of any one of embodiments 23-31, wherein thenucleic acid molecule of the adenovirus in the first composition furthercomprises a second polynucleotide sequence encoding a truncated HBV coreantigen consisting of the amino acid sequence of SEQ ID NO: 2.

Embodiment 33 is the method of embodiment 32, wherein the secondpolynucleotide sequence of the first composition is at least 90%identical to SEQ ID NO:

17.

Embodiment 34 is the method of embodiment 33, wherein the secondpolynucleotide sequence of the first composition comprises thepolynucleotide sequence of SEQ ID NO: 17.

Embodiment 35 is the method of any one of embodiments 32-34, wherein thefirst and second polynucleotide sequences of the first compositionencode a fusion protein comprising the truncated HBV core antigenoperably linked to the HBV polymerase antigen.

Embodiment 36 is the method of embodiment 35, wherein the fusion proteinof the first composition comprises the truncated HBV core antigenoperably linked to the HBV polymerase antigen via a linker.

Embodiment 37 is the method of embodiment 36, wherein the linker of thefirst composition comprises the amino acid sequence of (AlaGly)_(n), andn is an integer of 2 to 5, preferably the linker is encoded by apolynucleotide sequence comprising SEQ ID NO: 14.

Embodiment 38 is the method of embodiment 37, wherein the fusion proteinof the first composition comprises the amino acid sequence of SEQ ID NO:12.

Embodiment 39 is the method of any one of embodiments 35-38, wherein thefusion protein of the first composition further comprises a signalsequence, preferably the signal sequence comprises the amino acidsequence of SEQ ID NO: 6 or SEQ ID NO: 11, more preferably the signalsequence is encoded by the polynucleotide sequence of SEQ ID NO: 5 orSEQ ID NO: 10.

Embodiment 40 is the method of any one of embodiments 23-39, wherein thenon-naturally occurring nucleic acid molecule of the first compositionfurther comprises a promoter sequence, optionally one or more additionalregulatory sequences, preferably the promoter sequence comprises thepolynucleotide sequence of SEQ ID NO: 7, and the additional regulatorysequence is selected from the group consisting of an enhancer sequencesof SEQ ID NO: 8 or SEQ ID NO: 15, and a polyadenylation signal sequenceof SEQ ID NO: 16.

Embodiment 41 is the method of any one of embodiments 23-40, wherein thenon-naturally occurring nucleic acid molecule of the first compositiondoes not encode a HBV antigen selected from the group consisting of aHepatitis B surface antigen (HBsAg), a HBV envelope (Env) antigen, and aHBV L protein antigen.

Embodiment 42 is the method of any one of claims 23-41, wherein theenhanced immune response comprises an enhanced antibody response againstthe HBV antigen in the human subject.

Embodiment 43 is the method of embodiment 42, wherein the enhancedimmune response comprises an enhanced CD8+ T cell response against theHBV antigen in the human subject.

Embodiment 44 is the method of embodiment 42 or 43, wherein the enhancedimmune response comprises an enhanced CD4+ T cell response against theHBV antigen in the human subject.

Embodiment 45 is the method of any one of embodiments 23-44, wherein theadenovirus vector is an rAd26 or rAd35 vector.

Embodiment 46 is the method of any one of embodiments 23-45, whereinstep (b) is conducted 1-12 weeks after step (a).

Embodiment 47 is the method of any one of embodiments 23-45, whereinstep (b) is conducted 2-12 weeks after step (a).

Embodiment 48 is the method of any one of embodiments 23-45, whereinstep (b) is conducted at least 1 week after step (a).

Embodiment 49 is the method of any one of embodiments 23-45, whereinstep (b) is conducted at least 2 weeks after step (a).

Embodiment 50 is a vaccine combination comprising (a) a firstcomposition comprising an immunologically effective amount of anadenovirus vector comprising a first polynucleotide sequence encoding anHBV polymerase antigen comprising an amino acid sequence that is atleast 98% identical to SEQ ID NO:4; and (b) a second compositioncomprising an immunologically effective amount of a Modified VacciniaAnkara (MVA) vector comprising a second polynucleotide sequence encodingan HBV polymerase antigen comprising an amino acid sequence that is atleast 98% identical to SEQ ID NO: 4; wherein the first composition isadministered to the human subject for priming the immune response, andthe second composition is administered to the human subject one or moretimes for boosting the immune response.

Embodiment 51 is the vaccine combination of embodiment 50, wherein theHBV polymerase antigen of the first and second composition does not havereverse transcriptase activity and RNase H activity.

Embodiment 52 is the vaccine combination of embodiment 50 or 51, whereinthe HBV polymerase antigen of the first and second composition iscapable of inducing an immune response in a mammal against at least twoHBV genotypes, preferably the HBV polymerase antigen is capable ofinducing a T cell response in a mammal against at least HBV genotypes B,C, and D, and more preferably the HBV polymerase antigen is capable ofinducing a CD8 T cell response in a human subject against at least HBVgenotypes A, B, C, and D.

Embodiment 53 is the vaccine combination of any one of embodiments50-52, wherein the HBV polymerase antigen of the first and secondcomposition comprises the amino acid sequence of SEQ ID NO: 4.

Embodiment 54 is the vaccine combination of any one of embodiments50-53, further comprising a polynucleotide sequence encoding a signalsequence operably linked to the HBV polymerase antigen of the first andsecond composition.

Embodiment 55 is the vaccine combination of embodiment 54, wherein thesignal sequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQID NO: 11, preferably the signal sequence is encoded by thepolynucleotide sequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 56 is the vaccine combination of any one of embodiments50-55, wherein the first and second polynucleotide sequence is at least90% identical to SEQ ID NO: 3.

Embodiment 57 is the vaccine combination of embodiment 56, wherein thefirst and second polynucleotide sequence comprises the polynucleotidesequence of SEQ ID NO: 3.

Embodiment 58 is the vaccine combination of any one of embodiments50-57, wherein the adenovirus vector of the first composition furthercomprises a third polynucleotide sequence and the MVA vector of thesecond composition further comprises a fourth polynucleotide sequence,wherein the third and fourth polynucleotide sequence encode a truncatedHBV core antigen consisting of the amino acid sequence of SEQ ID NO: 2.

Embodiment 59 is the vaccine combination of embodiment 58, wherein thethird and fourth polynucleotide sequence is at least 90% identical toSEQ ID NO: 1.

Embodiment 60 is the vaccine combination of embodiment 59, wherein thethird and fourth polynucleotide sequence comprises the polynucleotidesequence of SEQ ID NO: 1.

Embodiment 61 is a vaccine combination comprising (a) a firstcomposition comprising an immunologically effective amount of a ModifiedVaccinia Ankara (MVA) vector comprising a first polynucleotide sequenceencoding an HBV polymerase antigen comprising an amino acid sequencethat is at least 98% identical to SEQ ID NO:4; and (b) a secondcomposition comprising an immunologically effective amount of anadenovirus vector comprising a second polynucleotide sequence encodingan HBV polymerase antigen comprising an amino acid sequence that is atleast 98% identical to SEQ ID NO:4; wherein the first composition isadministered to the human subject for priming the immune response, andthe second composition is administered to the human subject one or moretimes for boosting the immune response.

Embodiment 62 is the vaccine combination of embodiment 61, wherein theHBV polymerase antigen of the first and second composition does not havereverse transcriptase activity and RNase H activity.

Embodiment 63 is the vaccine combination of embodiment 61 or 62, whereinthe HBV polymerase antigen of the first and second composition iscapable of inducing an immune response in a mammal against at least twoHBV genotypes, preferably the HBV polymerase antigen is capable ofinducing a T cell response in a mammal against at least HBV genotypes B,C, and D, and more preferably the HBV polymerase antigen is capable ofinducing a CD8 T cell response in a human subject against at least HBVgenotypes A, B, C, and D.

Embodiment 64 is the vaccine combination of any one of embodiments61-63, wherein the HBV polymerase antigen of the first and secondcomposition comprises the amino acid sequence of SEQ ID NO: 4.

Embodiment 65 is the vaccine combination of any one of embodiments61-64, further comprising a polynucleotide sequence encoding a signalsequence operably linked to the HBV polymerase antigen of the first andsecond composition.

Embodiment 66 is the vaccine combination of embodiment 65, wherein thesignal sequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQID NO: 11, preferably the signal sequence is encoded by thepolynucleotide sequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 67 is the vaccine combination of any one of embodiments61-66, wherein the first and second polynucleotide sequence is at least90% identical to SEQ ID NO: 3.

Embodiment 68 is the vaccine combination of embodiment 67, wherein thefirst and second polynucleotide sequence comprises the polynucleotidesequence of SEQ ID NO: 3.

Embodiment 69 is the vaccine combination of any one of embodiments61-68, wherein the MVA vector of the first composition further comprisesa third polynucleotide sequence and the adenovirus vector of the secondcomposition further comprises a fourth polynucleotide sequence, whereinthe third and fourth polynucleotide sequence encode a truncated HBV coreantigen consisting of the amino acid sequence of SEQ ID NO: 2.

Embodiment 70 is the vaccine combination of embodiment 69, wherein thethird and fourth polynucleotide sequence is at least 90% identical toSEQ ID NO: 1.

Embodiment 71 is the vaccine combination of embodiment 70, wherein thethird and fourth polynucleotide sequence comprises the polynucleotidesequence of SEQ ID NO: 1.

Embodiment 72 is the vaccine combination of any one of embodiments50-71, which is a kit.

Embodiment 73 is a method of enhancing an immune response in a humansubject, the method comprising (a) administering to the human subject afirst composition comprising an immunologically effective amount of afirst plasmid comprising a first non-naturally occurring nucleic acidmolecule comprising a first polynucleotide sequence encoding an HBVpolymerase antigen comprising an amino acid sequence that is at least98% identical to SEQ ID NO: 4 and a second plasmid comprising a secondnon-naturally occurring nucleic acid molecule comprising a secondpolynucleotide sequence encoding a truncated HBV core antigen consistingof the amino acid sequence of SEQ ID NO: 2; and (b) administering to thehuman subject a second composition comprising an immunologicallyeffective amount of the MVA vector of any one of embodiments 1-21; tothereby obtain an enhanced immune response against the HBV antigen inthe human subject.

Embodiment 74 is the method of embodiment 73, wherein the HBV polymeraseantigen of the first composition does not have reverse transcriptaseactivity and RNase H activity.

Embodiment 75 is the method of embodiment 73 or 74, wherein the firstcomposition is for priming the immune response and the secondcomposition is for boosting the immune response.

Embodiment 76 is the method of any one of embodiments 73-75, wherein theHBV polymerase antigen of the first composition is capable of inducingan immune response in the human subject against at least two HBVgenotypes, preferably the HBV polymerase antigen is capable of inducinga T cell response in the human subject against at least HBV genotypes B,C, and D, and more preferably the HBV polymerase antigen is capable ofinducing a CD8 T cell response in the human subject against at least HBVgenotypes A, B, C, and D.

Embodiment 77 is the method of any one of embodiments 73-76, wherein theHBV polymerase antigen of the first composition comprises the amino acidsequence of SEQ ID NO: 4.

Embodiment 78 is the method of any one of embodiments 73-77, furthercomprising a polynucleotide sequence encoding a signal sequence operablylinked to the HBV polymerase antigen of the first composition.

Embodiment 79 is the method of embodiment 78, wherein the signalsequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:11, preferably the signal sequence is encoded by the polynucleotidesequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 80 is the method of any one of embodiments 73-79, wherein thefirst polynucleotide sequence of the first composition is at least 90%identical to SEQ ID NO: 20.

Embodiment 81 is the method of embodiment 80, wherein the firstpolynucleotide sequence of the first composition comprises thepolynucleotide sequence of SEQ ID NO: 20.

Embodiment 82 is the method of embodiments 73-81, wherein the secondpolynucleotide sequence of the first composition is at least 90%identical to SEQ ID NO: 18.

Embodiment 83 is the method of embodiment 82, wherein the secondpolynucleotide sequence of the first composition comprises thepolynucleotide sequence of SEQ ID NO: 18.

Embodiment 84 is the method of any one of embodiments 73-83, wherein thefirst and second polynucleotide sequences of the first compositionfurther comprise a promoter sequence, optionally one or more additionalregulatory sequences, preferably the promoter sequence comprises thepolynucleotide sequence of SEQ ID NO: 7, and the additional regulatorysequence is selected from the group consisting of an enhancer sequenceof SEQ ID NO: 8 or SEQ ID NO: 15, and a polyadenylation signal sequenceof SEQ ID NO: 16.

Embodiment 85 is the method of any one of claims 73-84, wherein theenhanced immune response comprises an enhanced antibody response againstthe HBV antigen in the human subject.

Embodiment 86 is the method of embodiment 85, wherein the enhancedimmune response comprises an enhanced CD8+ T cell response against theHBV antigen in the human subject.

Embodiment 87 is the method of embodiment 85 or 86, wherein the enhancedimmune response comprises an enhanced CD4+ T cell response against theHBV antigen in the human subject.

Embodiment 88 is the method of any one of embodiments 73-87, whereinstep (b) is conducted 1-12 weeks after step (a).

Embodiment 89 is the method of any one of embodiments 73-87, whereinstep (b) is conducted 2-12 weeks after step (a).

Embodiment 90 is the method of any one of embodiments 73-87, whereinstep (b) is conducted at least 1 week after step (a).

Embodiment 91 is the method of any one of embodiments 73-87, whereinstep (b) is conducted at least 2 weeks after step (a).

Embodiment 92 is a method of enhancing an immune response in a humansubject, the method comprising (a) administering to the human subject afirst composition comprising an immunologically effective amount of theMVA vector of any one of embodiments 1-21; and (b) administering to thehuman subject a second composition comprising an immunologicallyeffective amount of a first plasmid comprising a non-naturally occurringnucleic acid molecule comprising a first polynucleotide sequenceencoding an HBV polymerase antigen comprising an amino acid sequencethat is at least 98% identical to SEQ ID NO: 4 and a second plasmidcomprising a non-naturally occurring nucleic acid molecule comprising asecond polynucleotide sequence encoding a truncated HBV core antigenconsisting of the amino acid sequence of SEQ ID NO: 2; to thereby obtainan enhanced immune response against the HBV antigen in the humansubject.

Embodiment 93 is the method of embodiment 92, wherein the HBV polymeraseantigen of the second composition does not have reverse transcriptaseactivity and RNase H activity.

Embodiment 94 is the method of embodiment 92 or 93, wherein the firstcomposition is for priming the immune response and the secondcomposition is for boosting the immune response.

Embodiment 95 is the method of any one of embodiments 92-94, wherein theHBV polymerase antigen of the second composition is capable of inducingan immune response in the human subject against at least two HBVgenotypes, preferably the HBV polymerase antigen is capable of inducinga T cell response in the human subject against at least HBV genotypes B,C, and D, and more preferably the HBV polymerase antigen is capable ofinducing a CD8 T cell response in the human subject against at least HBVgenotypes A, B, C, and D.

Embodiment 96 is the method of any one of embodiments 92-95, wherein theHBV polymerase antigen of the second composition comprises the aminoacid sequence of SEQ ID NO: 4.

Embodiment 97 is the method of any one of embodiments 92-96, furthercomprising a polynucleotide sequence encoding a signal sequence operablylinked to the HBV polymerase antigen of the second composition.

Embodiment 98 is the method of embodiment 97, wherein the signalsequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:11, preferably the signal sequence is encoded by the polynucleotidesequence of SEQ ID NO: 5 or SEQ ID NO: 10.

Embodiment 99 is the method of any one of embodiments 92-98, wherein thefirst polynucleotide sequence of the second composition is at least 90%identical to SEQ ID NO: 20.

Embodiment 100 is the method of embodiment 99, wherein the firstpolynucleotide sequence of the second composition comprises thepolynucleotide sequence of SEQ ID NO: 20.

Embodiment 101 is the method of embodiments 92-100, wherein the secondpolynucleotide sequence of the second composition is at least 90%identical to SEQ ID NO: 18.

Embodiment 102 is the method of embodiment 101, wherein the secondpolynucleotide sequence of the second composition comprises thepolynucleotide sequence of SEQ ID NO: 18.

Embodiment 103 is the method of any one of embodiments 92-102, whereinthe first and second polynucleotide sequences of the second compositionfurther comprise a promoter sequence, optionally one or more additionalregulatory sequences, preferably the promoter sequence comprises thepolynucleotide sequence of SEQ ID NO:7, and the additional regulatorysequence is selected from the group consisting of an enhancer sequenceof SEQ ID NO: 8 or SEQ ID NO: 15, and a polyadenylation signal sequenceof SEQ ID NO: 16.

Embodiment 104 is the method of any one of claims 92-103, wherein theenhanced immune response comprises an enhanced antibody response againstthe HBV antigen in the human subject.

Embodiment 105 is the method of embodiment 104, wherein the enhancedimmune response comprises an enhanced CD8+ T cell response against theHBV antigen in the human subject.

Embodiment 106 is the method of embodiment 104 or 105, wherein theenhanced immune response comprises an enhanced CD4+ T cell responseagainst the HBV antigen in the human subject.

Embodiment 107 is the method of any one of embodiments 92-106, whereinstep (b) is conducted 1-12 weeks after step (a).

Embodiment 108 is the method of any one of embodiments 92-106, whereinstep (b) is conducted 2-12 weeks after step (a).

Embodiment 109 is the method of any one of embodiments 92-106, whereinstep (b) is conducted at least 1 week after step (a).

Embodiment 110 is the method of any one of embodiments 92-106, whereinstep (b) is conducted at least 2 weeks after step (a).

Embodiment 111 is the method of any one of embodiments 92-106, whereinstep (b) is conducted at least 4 weeks after step (a).

Embodiment 112 is the method of any one of embodiments 92-106, whereinstep (b) is conducted at least 8 weeks after step (a).

Embodiment 113 is the method of any one of embodiments 92-106, whereinstep (b) is conducted at least 12 weeks after step (a).

EXAMPLES

The following examples of the application are to further illustrate thenature of the application. It should be understood that the followingexamples do not limit the invention and the scope of the invention is tobe determined by the appended claims.

Example 1: Generation of HBV Core and Pol Antigen Sequences

T-cell epitopes on the hepatitis core protein are considered importantfor elimination of hepatitis B infection and hepatitis B viral proteins,such as polymerase, may serve to improve the breadth of the response.Thus, hepatitis B core and polymerase proteins were selected as antigensfor the design of a therapeutic hepatitis B virus (HBV) vaccine.

Derivation of HBV Core and Polymerase Antigen Consensus Sequences

HBV pol and core antigen consensus sequences were generated based on HBVgenotypes B, C, and D. Different HBV sequences were obtained fromdifferent sources and aligned separately for core and polymeraseproteins. Original sequence alignments for all subtypes (A to H) weresubsequently limited to HBV genotypes, B, C, and D. Consensus sequenceswere defined for each protein alignment in each subtype separately andin all joint BCD sequences. In variable alignment positions, the mostfrequent amino acid was used in the consensus sequence.

Optimization of HBV Core Antigen

The HBV core antigen consensus sequence was optimized by making twodeletions contained in the native viral protein. The first deletion wasa deletion of the N-terminal extension of the core protein constitutingthe pre-core “zinc finger” portion, because reports in the literaturehave indicated that the virus utilizes this sequence to induce toleranceto viral proteins in infected individuals. The second deletion was adeletion of thirty-four amino acids corresponding to the C-terminalhighly positively charged segment, which is required for pre-genomeencapsidation and productive viral positive-strand DNA synthesis in theviral life-cycle.

Optimization of the HBV Pol Antigen

The HBV pol antigen consensus sequence was optimized by changing fourresidues to remove reverse transcriptase and RNAseH enzymaticactivities. In particular, the aspartate residues (D) were changed toasparagine residues (N) in the “YXDD” motif of the reverse transcriptasedomain to eliminate any coordination function, and thus nucleotide/metalion binding. Additionally, the first aspartate residue (D) was changedto an asparagine residue (N) and the first glutamate residue (E) waschanged to a glutamine residue (A) in the “DEDD” motif of the RNAseHdomain to eliminate Mg2+ coordination. Additionally, the sequence of theHBV pol antigen was codon optimized to scramble the internal openreading frames for the envelope proteins, including the S protein andversions of the S protein with the N-terminal extensions pre-S1 andpre-S2.

As a result, open reading frames for the envelope proteins (pre-S1,pre-S2, and S protein) and the X protein were removed.

Selection of Signal Peptide for Efficient Protein Secretion

Three different signal peptides introduced in frame at the N-terminus ofthe HBV core antigen were evaluated: (1) Ig heavy chain gamma signalpeptide SPIgG (BAA75024.1); (2) the Ig heavy chain epsilon signalpeptide SPIgE (AAB59424.1); and (3) the Cystatin S precursor signalpeptide SPCS (NP 0018901.1). Signal peptide cleavage sites wereoptimized in silico for core fusion using the Signal P predictionprogram. Secretion efficiency was determined by analyzing core proteinlevels in the supernatant. Western blot analysis of core antigensecretion using the three different signal peptides fused at theN-terminus demonstrated that the Cystatin S signal peptide resulted inthe most efficient protein secretion.

Example 2: Generation of Adenoviral Vectors Expressing a Fusion ofTruncated HBV Core Antigen with HBV Pol Antigen

An adenovirus vector was created to express a fusion protein of atruncated HBV core antigen and a HBV pol antigen from a single openreading frame. Additional configurations for the expression of the twoproteins (e.g., the truncated HBV core antigen and the HBV pol antigen),e.g. using two separate expression cassettes, or using a 2A-likesequence to separate the two sequences, can also be envisaged.

Design of Expression Cassettes for Adenoviral Vectors

The expression cassettes (diagrammed in FIG. 2A and FIG. 2B) comprisethe CMV promoter (SEQ ID NO:7), an intron (SEQ ID NO:15) (a fragmentderived from the human ApoAI gene—GenBank accession X01038 base pairs295-523, harboring the ApoAI second intron), followed by the optimizedcoding sequence—either core alone or the core and polymerase fusionprotein preceded by a human immunoglobulin secretion signal codingsequence (SEQ ID NO:10), and followed by the SV40 polyadenylation signal(SEQ ID NO:16).

A secretion signal was included because of past experience showingimprovement in the manufacturability of some adenoviral vectorsharboring secreted transgenes, without influencing the elicited T-cellresponse (mouse experiments).

The last two residues of the Core protein (VV) and the first tworesidues of the Polymerase protein (MP) if fused results in a junctionsequence (VVMP) that is present on the human dopamine receptor protein(D3 isoform), along with flanking homologies.

The interjection of an AGAG linker between the core and the polymerasesequences eliminates this homology and returned no further hits in aBlast of the human proteome.

Example 3: Generation of MVA Vectors Expressing a HBV Core Antigen and aHBV Pol Antigen

An MVA vector has been designed to encode each of the HBV Core and Polcoding sequences of the application. Each of the HBV Core and Pol codingsequences were inserted into an MVA vector at IGR44/45, each under thecontrol of a separate promoter. Additional configurations for theexpression of the two proteins, e.g. using a single expression cassettewherein the Core and Pol antigen comprise a fusion protein, oralternatively utilizing a 2A-like sequence to separate the twosequences, can also be envisaged. Further, additional and/or alternativeinsertions sites in the MVA vector can also be envisaged, e.g.,inserting each of the HBV Core and Pol coding sequences into the same ordifferent insertion sites.

Design of Expression Cassettes for MVA Vectors

The expression cassettes (diagrammed in FIG. 2C) are comprised of thePr13.5 long promoter (SEQ ID NO: 25) adjacent to and directingexpression of the HBV Core antigen and the PrHyb promoter (SEQ ID NO:26) adjacent to and directing expression of the HBV Pol antigen. The HBVcore coding sequence comprises SEQ ID NO: 1 and the HBV Pol codingsequence comprises SEQ ID NO: 3. Each of SEQ ID NOs: 1 and 3 weremodified by eliminating negative cis-acting sites and by adjusting theGC content. Furthermore, each of SEQ ID NOs: 1 and 3 were codonoptimized for human codon usage without affecting the amino acidsequence. Each of SEQ ID NOs: 1 and 3 comprises an additional earlytermination signals (TTTTTNT (SEQ ID NO: 28)) arranged adjacent to thestop codon.

Example 4: Immunogenicity of Combinations of HBV Adenoviral Vectors andHBV MVA Vectors in Mice

Materials and Methods

Vector design: Two adenoviral vectors expressing either Core alone (anHBV core antigen having the amino acid sequence of SEQ ID NO: 2), orPolymerase (an HBV pol antigen having the amino acid sequence of SEQ IDNO: 4) in addition to Core as a fusion protein expressed from a singleopen reading frame were used. For this, sequences were designed insilico to provide a consensus for the B, C and D genotypes of thehepatitis B virus. The expression cassettes comprise the CMV promoter,an ApoAI intron, a human immunoglobulin secretion signal, followed bythe coding sequence—either Core alone or the Core and Polymerase fusionprotein and a SV40 polyadenylation signal.

The recombinant MVA vector is comprised of poxvirus promoter Pr13.5 (SEQID NO:25) linked to the core coding sequence (nucleotide sequence of SEQID NO:1, and polypeptide sequence of SEQ ID NO:2) and PrHyb (SEQ ID NO:26) linked to a nucleotide sequence encoding for polymerase (nucleotidesequence of SEQ ID NO: 3, and polypeptide sequence of SEQ ID NO: 4),both followed by a transcription termination sequence of TTTTTNT (SEQ IDNO: 28). The core coding sequence comprises an N-terminal immunoglobulinsecretion tag (SEQ ID NO: 11), and the polymerase coding sequencecomprises an N-terminal cystatin S signal sequence (SEQ ID NO:6). See,e.g., FIG. 2C.

In vivo immunogenicity study in mice: To evaluate the in vivoimmunogenicity of the combination of HBV adenoviral vectors and HBV MVA,F1 mice (C57BL/6×Balb/C) were prime-boost immunized intramuscularly withdifferent vector combinations. These immunogenicity studies focused ondetermining the cellular immune responses elicited by the HBV antigensCore and Polymerase.

Antigen-specific responses were analyzed and quantified by IFN-γenzyme-linked immunospot (ELISPOT) and intracellular cytokine production(TNF-alpha, IL-2 and IFN-γ) was detected by flow cytometry. In theseassays, isolated splenocytes of immunized animals were incubated withpeptide pools covering the Core protein, the Pol protein, or the smallpeptide leader and junction sequence (2 μg/ml of each peptide). Inaddition a MVA specific peptide (2 μg/ml) was used. The pools consist of15-mer peptides that overlap by 11 residues matching the genotypes ABCDconsensus sequence of the Core and Pol adenoviral vectors. The large 94kDa HBV Pol protein was split in the middle into two peptide pools. InELISPOT, IFN-γ release by a single antigen-specific T-cell wasvisualized by appropriate antibodies and subsequent chromogenicdetection as a colored spot on the microplate referred to asspot-forming cell (SFC). In ICS, the percentage of cytokine-releasingcells in a particular population (CD3-positive, CD4-positive orCD8-positive cells) was determined.

Results

Evaluation of immunogenicity of HBV adenoviral vectors and HBV MVAcombinations in mice: The purpose of the study was to evaluate theimmune response induced by the combination of HBV adenoviral vectors andHBV MVA after IM delivery into F1 mice. The administration to F1 micewas performed as summarized in Table 1. Animals received one HBVadenoviral vector immunization followed by a HBV MVA immunization 8weeks later. Splenocytes were collected one week after the lastimmunization.

TABLE 1 Mouse Immunization Experimental Design Prime Dose Boost DoseEndpt Group N Day 0 R (vp) Day 56 Route TCID50 Day 1 4 Core Pol fusion +Core IM 10⁸ — — — 63 2 4 Core Pol fusion + Core IM 10⁹ — — — 63 3 4 CorePol fusion + Core IM  10¹⁰ — — — 63 4 4 Core Pol fusion + Core IM 10⁸MVA IM 8.9 × 10⁷ 63 5 4 Core Pol fusion + Core IM 10⁹ MVA IM 8.9 × 10⁷63 6 4 Core Pol fusion + Core IM  10¹⁰ MVA IM 8.9 × 10⁷ 63 7 4 Core Polfusion IM 10⁸ — — — 63 8 4 Core Pol fusion IM 10⁹ — — — 63 9 4 Core Polfusion IM  10¹⁰ — — — 63 10 4 Core Pol fusion IM 10⁸ MVA IM 8.9 × 10⁷ 6311 4 Core Pol fusion IM 10⁹ MVA IM 8.9 × 10⁷ 63 12 4 Core Pol fusion IM 10¹⁰ MVA IM 8.9 × 10⁷ 63 13 4 Empty Vector IM  10¹⁰ EV IM — 63 IM:intramuscular; vp: viral particles; TCID50: 50% tissue culture infectivedose; MVA: Modified Vaccinia Ankara

HBV adenoviral vectors alone and in combination with HBV MVA vector,gave rise to Pol specificT cell responses in mice. Low-level coreresponses were induced by Core pol fusion+core adenoviral vectors andthese responses where amplified by boosting with HBV MVA vector. Thecombination of Core pol fusion adenovector and HBV MVA vector alsoinduced core responses (FIG. 3).

Pol responses are primarily mediated by CD8(+) T cells, whereas Coreresponses primarily involve CD4(+) T cells (FIGS. 4 and 5). Thecombination of Core pol fusion+core adenovectors and HBV MVA alsoinduced CD8(+) T cell driven core responses (FIG. 4).

Conclusion: The combination of HBV adenoviral vectors and HBV MVAvectors gives rise to T cell responses against core and pol in F1 mice.

Example 5: Immunogenicity of Combinations of HBV Adenoviral Vectors andHBV MVA Vectors in Non-Human Primates (NHPs)

In vivo immunogenicity study in NHPs: To evaluate the in vivoimmunogenicity of the combination of HBV adenoviral vectors and HBV MVAvectors, Mauritian cynomolgus monkeys were prime-boost-boost immunizedintramuscularly with different vector combinations. These immunogenicitystudies focused on determining the cellular immune responses elicited bythe HBV core and polymerase antigens.

Antigen-specific responses were analyzed and quantified by IFN-γenzyme-linked immunospot (ELISPOT) and intracellular cytokine production(TNF-alpha, IL-2 and IFN-γ) was detected by flow cytometry. In theseassays, PBMCs of immunized animals were incubated with peptide poolscovering the Core protein or the Pol protein (2 μg/ml of each peptide).The pools consist of 15-mer peptides that overlap by 11 residuesmatching the genotypes ABCD consensus sequence of the Core and Poladenoviral vectors. The large 94 kDa HBV Pol protein was split in themiddle into two peptide pools. In ELISPOT, IFN-γ release by a singleantigen-specific T-cell was visualized by appropriate antibodies andsubsequent chromogenic detection as a colored spot on the microplatereferred to as spot-forming cell (SFC). In intracellular cytokinestaining (ICS), the percentage of cytokine-releasing cells in aparticular population (CD3-positive, CD4-positive or CD8-positive cells)was determined.

Results

Evaluation of immunogenicity of HBV adenoviral vectors and HBV MVAvectors combinations in NHPs: The purpose of the study was to evaluatethe immune response induced by the combination of HBV adenoviral vectorsand HBV MVA vectors after IM delivery into Mauritian cynomolgus monkeys.The administration to NHPs was performed as summarized in Table 2.Animals received one HBV adenoviral vector immunization followed by aHBV MVA vector immunization 8 weeks later and again followed by a HBVadenoviral vector immunization 8 weeks later. PBMCs were collected twoweeks after each immunization.

TABLE 2 NHP Immunization Experimental Design Dose per Prime vector BoostDose Boost Dose Group N Day 0 R (vp) Day 56 R TCID50 Day 112 (vp) R 1 8Core Pol IM 5*10¹⁰ MVA IM 5*10⁸ Core Pol 1*10¹¹ IM fusion fusion 2 8Core Pol IM 5*10¹⁰ MVA IM 5*10⁸ Core Pol 1*10¹¹ IM fusion + Core fusionIM: intramuscular; vp: viral particles; TCID50: 50% tissue cultureinfective dose; MVA: Modified Vaccinia Ankara

Core pol fusion adenoviral vector alone and Core pol fusion+coreadenoviral vectors in combination with HBV MVA vector, gave rise torobust Pol and Core specific T cell responses in NHPs. Further boostingwith a Core pol fusion adenoviral vector did not further increase theresponse (FIG. 6).

Core and Pol responses in NHPs are mediated by both CD4(+) and CD8(+) Tcells. The combination of Core pol fusion adenovectors+core adenovectors(used as a prime) and HBV MVA (used as a boost) induced the highestCD4(+) Core specific and CD8(+) Pol specific T cell IFN-γ responses(FIG. 7).

These results demonstrate that the combination of HBV adenoviral vectorsand HBV MVA vectors gave rise to robust T cell responses against thecore and pol antigens in NHPs.

It will be appreciated by those skilled in the art that changes could bemade to the embodiments described above without departing from the broadinventive concept thereof. It is understood, therefore, that thisinvention is not limited to the particular embodiments disclosed, but itis intended to cover modifications within the spirit and scope of thepresent invention as defined by the present description.

REFERENCES

-   1. Cohen et al. “Is chronic hepatitis B being undertreated in the    United States?” J. Viral Hepat. (2011) 18(6), 377-83.-   2. Obeng-Adjei et al. “DNA vaccine cocktail expressing genotype A    and C HBV surface and consensus core antigens generates robust    cytotoxic and antibody responses and mice and Rhesus macaques”    Cancer Gene Therapy (2013) 20, 652-662.-   3. World Health Organization, Hepatitis B: Fact sheet No. 204    [Internet] 2015 March. Available from    http://www.who.nt/mediacentre/factsheets/fs204/en/.-   4. Belloni et al. “IFN-α inhibits HBV transcription and replication    in cell culture and in humanized mice by targeting the epigenetic    regulation of the nuclear cccDNA minichromosome” J. Clin.    Invest. (2012) 122(2), 529-537.-   5. Michel et al. “Therapeutic vaccines and immune-based therapies    for the treatment of chronic hepatitis B: perspectives and    challenges.” J. Hepatol. (2011) 54(6), 1286-1296.

It is claimed:
 1. A method of enhancing an immune response in a humansubject, the method comprising: (a) administering to the human subject afirst composition comprising an immunologically effective amount of anadenovirus vector comprising a non-naturally occurring nucleic acidmolecule comprising a first polynucleotide sequence encoding an HBVpolymerase antigen comprising an amino acid sequence that is at least98% identical to SEQ ID NO:4; and (b) administering to the human subjecta second composition comprising an immunologically effective amount of aModified Vaccinia Ankara (MVA) vector comprising a non-naturallyoccurring nucleic acid molecule comprising a first polynucleotidesequence encoding an HBV polymerase antigen comprising an amino acidsequence that is at least 98% identical to SEQ ID NO: 4; to therebyobtain an enhanced immune response against the HBV antigen in the humansubject.
 2. The method of claim 1, wherein the HBV polymerase antigen ofthe first composition is capable of inducing an immune response in thehuman subject against at least two HBV genotypes.
 3. The method of claim1, wherein the HBV polymerase antigen is capable of inducing a T cellresponse in the human subject against at least HBV genotypes B, C, andD.
 4. The method of claim 1, wherein the HBV polymerase antigen iscapable of inducing a CD8 T cell response in the human subject againstat least HBV genotypes A, B, C, and D.
 5. The method of claim 1, whereinthe HBV polymerase antigen of the first composition comprises the aminoacid sequence of SEQ ID NO:
 4. 6. The method of claim 1, wherein thefirst polynucleotide sequence of the first composition is at least 90%identical to SEQ ID NO:
 19. 7. The method of claim 1, wherein the firstpolynucleotide sequence of the first composition comprises thepolynucleotide sequence of SEQ ID NO:
 19. 8. The method of claim 1,wherein the enhanced immune response comprises at least one of anenhanced antibody response against the HBV antigen in the human subject,an enhanced CD8+ T cell response against the HBV antigen in the humansubject, and an enhanced CD4+ T cell response against the HBV antigen inthe human subject.
 9. The method of claim 1, wherein the adenovirusvector is an rAd26 or rAd35 vector.
 10. A method of enhancing an immuneresponse in a human subject, the method comprising: (a) administering tothe human subject a first composition comprising an immunologicallyeffective amount of a first plasmid comprising a first non-naturallyoccurring nucleic acid molecule comprising a first polynucleotidesequence encoding an HBV polymerase antigen comprising an amino acidsequence that is at least 98% identical to SEQ ID NO: 4; and (b)administering to the human subject a second composition comprising animmunologically effective amount of a Modified Vaccinia Ankara (MVA)vector comprising a non-naturally occurring nucleic acid moleculecomprising a first polynucleotide sequence encoding an HBV polymeraseantigen comprising an amino acid sequence that is at least 98% identicalto SEQ ID NO: 4; to thereby obtain an enhanced immune response againstthe HBV antigen in the human subject.
 11. The method of claim 10,wherein the HBV polymerase antigen of the first composition is capableof inducing an immune response in the human subject against at least twoHBV genotypes.
 12. The method of claim 10, wherein the HBV polymeraseantigen is capable of inducing a T cell response in the human subjectagainst at least HBV genotypes B, C, and D.
 13. The method of claim 10,wherein the HBV polymerase antigen is capable of inducing a CD8 T cellresponse in the human subject against at least HBV genotypes A, B, C,and D.
 14. The method of claim 10, wherein the HBV polymerase antigen ofthe first composition comprises the amino acid sequence of SEQ ID NO: 4.15. The method of claim 10, further comprising a polynucleotide sequenceencoding a signal sequence operably linked to the HBV polymerase antigenof the first composition.
 16. The method of claim 13, wherein the signalsequence comprises the amino acid sequence of SEQ ID NO: 6 or SEQ ID NO:11.
 17. The method of claim 13, wherein the signal sequence is encodedby the polynucleotide sequence of SEQ ID NO: 5 or SEQ ID NO:
 10. 18. Themethod of claim 10, wherein the first polynucleotide sequence of thefirst composition is at least 90% identical to SEQ ID NO:
 20. 19. Themethod of claim 10, wherein the first polynucleotide sequence of thefirst composition comprises the polynucleotide sequence of SEQ ID NO:20.
 20. The method of claim 10, wherein the enhanced immune responsecomprises at least one of an enhanced antibody response against the HBVantigen in the human subject, an enhanced CD8+ T cell response againstthe HBV antigen in the human subject, and an enhanced CD4+ T cellresponse against the HBV antigen in the human subject.